Abstract: This paper proposes a method of using Compass-1's short message transmission function to support space-based TT&C technology,using its time service function to support space-ground time difference measurement technology,and using its positioning function to support orbit determination technology for LEOs.Currently,YG-9,the first satellite carrying a Compass-1 user receiver,has validated the key technologies of space-based TT&C.The test on YG-9 has shown that the space-based TT&C functions well,the precision of space-ground time difference measurement can satisfy the requirements of onboard computer,and the orbit accuracy of YG-9 can achieve 1m in semi-major axes with only the four-way ranging data between YG-9 and Compass-1.Finally,this paper analyzes the application foreground of Compass-1 space-based TT&C technology.