Hi ​@wangtel,

you might rather want to ask this question at a Google Fit forum rather than here, there’d be a higher chance of getting help. 

On a side note, to be honest I don't understand how a service can not allow users to delete their own activity data. That sounds like a huge privacy issue to me…

Edit to add: if you're based in the EU, you can request that Google deletes that activity. Them rejecting to do so would violate the GDPR regulations. 

Thanks,I understand what you mean,but I am not in EU.

And I think this has something to do with the api agreement between Strava and Google. Since Google requires that only third-party apps can delete activities, the corresponding apps should provide relevant functions.

Understood… well - you can try deleting the activity from your Strava and see whether it removes it also from the google fit account, to test whether it's a working solution. If needed, you can then restore the activity here, https://www.strava.com/athlete/training/recently_deleted though you’d probably want to disconnect the strava x google fit integration first, to make sure that it won't re-sync again.

Thank you for your suggestions. I have tried,it doesn't work.

sorry to hear this hopefully someone will be able to help / advise some trick - I tried a quick google search and it seems that this problem has been there for many years, but none of the discussions / reddit posts etc included a solution...

Hello ​@wangtel - thanks for writing in here. This is a known issue with Google Fit, you can also view similar experiences here: https://support.google.com/fit/thread/16598538?hl=en

If you would no longer like future activities to sync with Google Fit, I would recommend disconnecting services between Google Fit and Strava from within your Strava app settings here: https://www.strava.com/settings/apps as well as from within the Google Fit mobile application. 

Unfortunately, we do not have any visibility or control into activities stored on Google Fit. For any further info, we suggest reaching out to the company directly. To provide some context, we have a publicly available API that hundreds of external developers use to integrate with Strava data. These integrations are built and maintained by those 3rd party developers which means that any troubleshooting questions are better directed their way.
 
Sorry about that and good luck!