How to take that kind of stroboscopic photo on the mobile phone?

This is more difficult. But it is not impossible. You shoot in camera mode. The background is black. Then find a support point. It's gone. Take out the video later. Just put the video together.

Stroboscopic photos are difficult to use even with SLR. Because it needs flash support. I happen to have a lamp to support this. Black background, long exposure.

There's another way. Just make your own shooting software, and then control the flash outside through WIFI and Bluetooth. The cost is too high.

Finally, there is another way. Block the light with wheels. There are many gaps in the wheel. It is equivalent to controlling the light into a shutter.

The mobile phone does not support long shutter time or fast shooting. So at present, there is no other way to take stroboscopic photos except camera mode.

If you look at Casio or some special micro-singles, maybe they support simple strobes.

I know there used to be a canon, and it took panoramic photos. Can realize stroboscopic.

Maybe the mobile phone can also refer to this idea and shoot the panoramic mode first. Then let a person do different actions on a black background. Finally, the panorama is synthesized and turned into a stroboscopic photo.