1. Mirroring and Cluster Control Are Not the Same Thing
A lot of people treat screen mirroring as if it were cluster control. Mirroring only covers half of it, the seeing half, and the other half comes from HarmonyOS automation scripts. You need to see the screen and act on it. Both together is what makes a working setup.
On HarmonyOS, mirroring lives inside the HarmonyOS central control. From connecting a device to seeing a picture, it is one chain: the device connects to the central control, automation is enabled, the mirroring client pulls the stream, and the master control window renders it. Break any link and you get a black window or clicks that do nothing.
This article walks that chain for HarmonyOS Next: how to get in, how master control and sync relate, how input travels, and where file transfer and OCR live.
2. How to Open It
Open mirroring from the central control. Do not launch the mirroring client on its own, because it will tell you the service needs to be started first.
The path is: double-click the central control executable and log in, confirm the device is in the list with service status reading Yes, then click group mirroring in the top toolbar and choose the new interface. The first launch shows a short onboarding flow, and picking a light or dark theme finishes it.
Once inside, the screen is split into four regions: the workbench and more menu on the left, the thumbnail grid in the middle, the master control area on the right, and system settings at the edge. Day to day you only touch the first three.
3. Pick the Right Mirroring Scene
HarmonyOS screen mirroring has a setting most platforms do not: mirroring scenes. It decides which channel carries your gestures.
Under mirroring settings in system settings there are three options.
| Scene | Gesture channel | When to use it |
|---|---|---|
| USB plus automation service | Proxy | The default, and right for normal work |
| USB plus Bluetooth HID | Bluetooth HID | When gestures should come from the ESP32 board |
| Custom | Manual | When you need to tune the parameters yourself |
The first one is enough for almost everyone. Switch to the second only when a Bluetooth board is bound and you want gestures to leave through it. The classic symptom of a wrong scene is a normal picture with unresponsive clicks, which is why “the picture is there but nothing responds” should send you back to this setting rather than to the device.
4. Master Control and Sync Actions
In the thumbnail grid, each device is a small preview. To operate a phone directly from the computer, set it as master control: right-click the thumbnail and choose set as master control. It then renders in the large area.
The point of master control is that its actions can be copied outward. Turn on sync actions in the sidebar, and your clicks and swipes in the master control area are repeated on every selected device.
Sync has two conditions that must both hold, and this is where people get stuck. The target devices must be selected, and the control, mouse, and keyboard switches above the master control title bar must be turned on as needed. Control is the master switch, mouse governs pointer actions, keyboard governs typing. Leave mouse off and swipes simply will not sync.
There is also a sync random delay worth adjusting. When every device performs an identical action in the same millisecond, it looks unnatural, and a little randomized delay fixes that.
The master control can render as a floating window, a separate window, or embedded in the page. Floating suits working while watching, separate suits dual monitors.
5. Input, Images, and Text
Typing has two modes, set in system settings. The system default sends input through the proxy, which handles Chinese, long text, and emoji. Follow-HID uses Bluetooth keyboard key codes, fine for English and shortcuts but awkward for Chinese, so switch back for Chinese every time.
Above the master control area there is an input box that sends text straight to the master device, which is handy for fixing a caption or adding one comment.
Image and video transfer lives in the sidebar workbench, and also in the thumbnail right-click menu. Image transfer supports choosing a folder per device for batch upload, which saves real time during batch publishing.
6. OCR and Canned Replies
From central control version 3.1.0 onward, PP-OCRv6 ships built in. The OCR entry point is on the OCR page in system settings. Pick the engine, optionally enable releasing resources after recognition, then right-click a thumbnail and choose recognize screen text.
In HarmonyOS cluster control, OCR is less about replacing scripts and more about verification. After a batch publish or batch operation finishes, recognizing the screen confirms the content actually landed, which is more meaningful than trusting a script’s success code alone.
Canned replies cover customer service. Select several thumbnails, right-click, and you get multi-device replies so one action can send different messages to different phones. None of this requires writing HarmonyOS scripts. It is all interface work, which is the lowest-effort part of the whole platform.
7. When the Picture Stutters
Stutter almost always comes from the chain rather than the software. Work through it in this order.
Network first: bandwidth, packet loss, wireless interference. Prefer wired connections on a LAN, and check router capacity in wireless setups.
Then the device side: a phone running a heavy task encodes and pushes its stream more slowly, and the picture follows.
Then the PC: pulling dozens of streams at once costs GPU and CPU, and the save-bandwidth-on-group-switch option in the sidebar stops streams for groups you have navigated away from.
One more setting matters more than people expect: thumbnail resolution. If the grid is only there so you can glance at status, there is no reason to pull it at full resolution.
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