For the sensitivity problem of radar ship attitude angle, the influence of the viewing angle on the estimation accuracy of the ship’s length is analyzed. A method of the high range resolution profile (HRRP)  viewing angle extraction based on radar track is proposed. Firstly, a simplified radar ship motion model is established, then the track is preprocessed, the target’s state of motion and speed are estimated. The robust regression method is used to simulate the curves and estimate the viewing angle parameter of the ship target. The angle estimated by this algorithm can be used in the radar ship target automatic recognition system and ship length estimation.The measured data shows that the estimated error accuracy is less than 5°. This method is easy to practice and has high engineering application value.