Angular disturbance isolation evaluated by a isolation index is an important function of a seeker.In order to realize a quick test of the isolation index, the principle of disturbance isolation of the seeker is analyzed,and a model of the isolation index is deduced.Then,by analyzing the structure of stabilization loop of the seeker,an isolation index test method based on the dSPACE hardware-in-the-loop simulation system is proposed to be used in the stage of controller adjusting.According to adding a disturbance signal in the stabilization loop,this method can test the isolation index quickly without simulating missile advantages in disturbance by the flight simulation turntable.Compared with the traditional methods,this method has simple structures and fast test velocities.Using this method,the isolation index of stabilization loop of an infrared imaging seeker is tested and the results show that the test error is less than 2 dB compared with that of the traditional method,which indicates that this method is feasible to test isolation indexes of seekers or other optoelectronic platforms on moving vehicles.