This paper describes a telecommand interference of spacecraft for business communication signals, in order to solve this problem, to carry out the investigation and theoretical analysis of the test work. By testing and verification, identified as equipment turned off the memory of a latent pathway leading to the remote command and 10 MHz local oscillator signal modulated by power divider network, the local oscillator signal is fed back to the entrance of other receivers, causing reception machine phase noise becomes large, so that the communication signal errors during transmission. To solve this problem, taken to increase the reverse isolation circuit programs to increase the reference signal between the receiver and remote control commands isolation, to solve the interference problem by testing to confirm the communication signal error no longer occurs.