Hello,when i pilot with the AP in microsoft flight simulator 2020 airbus a320 FLYBYWIRE, and want to turn with the heading ater a fews seconds the AP is disconnect.

I have moved your topic to the proper forum for getting answers to your question.

Are you in managed mode and then pulling the heading knob resulting in the AP disconnect?

Hello,i` m not in managed mode,i have the AP for altitude,Thank you for the help

It is meant to work that way. If you operate the stick, the AP disconnects.

If you want to keep using the AP you have to rotate the HDG knob to the desired heading and pull it (left mouse click on the lower side of the knob). I suggest watching Youtube tutorials, these are very basic operations.

Thank you Mr

https://www.youtube.com/@billhobc2594 is my you tube channel watch the video A320

19 minutes ago, BILL72 said:

https://www.youtube.com/@billhobc2594 is my you tube channel watch the video A320

Very sorry to tell you, but you're doing so much wrong with this aircraft. I would suggest you check out some youtube videos and learn how to handle the A320. I hope you don't understand this as critisism. We all began at some point.

For your particular question: your FMA (top of your PFD) shows that the plane is still in RWY track mode. Means: it keeps the rwy heading. This has several reasons. Roughly speaking, the plane doesn't know what you're doing. Try to pull the HDG bug again this should switch it to HDG mode.

8 hours ago, BILL72 said:

https://www.youtube.com/@billhobc2594 is my you tube channel watch the video A320

Better start with these: 

https://docs.flybywiresim.com/pilots-corner/beginner-guide/overview/

https://www.youtube.com/results?sp=mAEB&search_query=real+a320+pilot

Thank you for your help mr and watsi