The spacecraft's electronics and electrical systems is very complex, which includs the control system, telemetry system, measurement system, security system and so on, the interference inside and outside system is very serious. If lacks of careful consideration and appropriate measurement, it will cause poor system performance, even lead to the launch failure. This paper established models of aircraft and typical antennas on aircraft, compared the performance of the same antenna in HFSS and FEKO, and simulated the electromagnetic environment on the aircraft when all the he antennas were at work. The results of electromagnetic environment can offer a reference whether it would affect other electronic equipment.