In the flight test of post data processing of trajectory for obtaining higher precision of tracking position correction results, the correction method was put forward by using the attitude rotation matrix from strapdown inertial navigation system, to solve the problem that is difficult to accurately correct with the known size of target tracking correction parts. According to the quaternion information extracted from telemetry data of the strapdown inertial navigation system, the rotation matrix was calculated to correct the tracking position parameters. Meanwhile, by using the relationships of coordinate systems in the testing and modifying the effect of vertical deflection, the parameter precision was good. According to the simulation of test scene, the data was compared and verified with the commonly used velocity vector correction method. The results show that the method is feasible based on the attitude, and its result was correct. Moreover, it achieved the accuracy of post data processing and met the outcome assessment requirements.