The invention provides a constellation satellite measurement and control signal interference power estimation method. According to a constellation satellite position, a ground measurement and control station position and an antenna pattern, a target satellite measurement and control channel AGC value and transponder single-machine real measurement data, a constellation interference satellite interference signal power level is accurately estimated. The method can be used for constellation satellite measurement and control interference influence analysis, a constellation satellite measurement and control signal interference fault phenomenon can be simulated really through setting a constellation satellite measurement and control subsystem physical simulation and countermeasure verification platform, and the method is used for system level interference fault positioning and processing countermeasure verification.