The invention relates to an combined navigation and photoelectric detection integrative 
system, which comprises an 
inertia measurement unit IMU, a GPS receiving 
system, an integrated computer and a photoelectric 
sight-stabilizing instrument, wherein the 
inertia measurement unit IMU comprises three gyroscopes and three accelerometers; the integrated computer acquires the output information of the 
inertia measurement unit IMU and the GPS receiving 
system to realize that (1) inertia and GPS combined navigation resolving is carried out by combining a strapdown inertial navigation resolving 
algorithm and a 
Kalman filtering algorithm to obtain the position, the speed and the attitude of a carrier, and meanwhile estimate the drift of the gyroscopes of the inertia measurement unit IMU; (2) the stable instruction angular speed of an 
optical axis is calculated and the photoelectric 
sight-stabilizing instrument is controlled to realize the stability of the 
optical axis, the 
gyroscope drift estimated by the combined 
navigation system is utilized to compensate the stable error of the 
optical axis to improve the stable precision of the optical axis of the photoelectric 
sight-stabilizing instrument; and (3) the target search instruction angle is calculated and the photoelectric sight-stabilizing instrument is controlled to rapidly search and lock a target by utilizing the position and the attitude information obtained by combined navigation resolving by 
combing the position information of the target. The invention greatly reduces the volume, the weight and the cost of the system and meanwhile improves the performance of subsystems.