Abstract: There are two models in the research of seeker disturbance rejection rate which are the model based on inertial benchmark and the model based on missile benchmark. The physical mechanism of seeker disturbance rejection rate was studied. The diversity between two models was contrasted. The influences of disturbance torque on disturbance rejection rate were investigated for the model based on inertial benchmark. The lag compensation was designed to reduce disturbance rejection rate. Results indicate that, compared with the model based on missile benchmark, the model based on inertial benchmark describes the causation that disturbance rejection rate engenders more clearly, and the lag compensation can reduce disturbance rejection rate induced by disturbance torque effectively.