I used chipmixer in March. I thought the private key he gave me would be deleted, but it turned out that it was not deleted. On March 16, my btc was transferred by the police.
It is the police that seized the chipmixer so do not expect them to return your money. By the way ou are not alone here as Chipmixer Shuttered and $46.5 Million Seized
Quote
On March 15, national authorities took down the platform’s infrastructure and seized four servers, approximately 1,909 BTC from 55 transactions (worth approximately $46.5 million), and 7 TB of data.
I hope your money will be very less which is being lost in this operation.
I didn't commit a crime, it's just for privacy, so is there any way to recover my btc 
No one is going to take this as an excuse and return our money. The authorities don't like privacy and they want everything to be transparent. They may go to any level to get in implemented.