Aiming at the problem of the limited application scope of water-pulley model, a method for smoothing the tug track to obtain the track of the sonar array and estimate the array shape was proposed. By analyzing the steady-state vibration response characteristics of the array, it is considered that each point on the sonar array moves along the same track. The smoothing window was designed to smooth the tug track into the track of sonar array during circular maneuver, and was extended to the scene of course-change maneuvering. A part of the window was used to smooth the track portion, whose distance from the tug is less than the width of the smooth window, to obtain the current cable shape, so as to estimate the shape of the whole array during the course-change maneuvering. The simulation results show that if the array consists of 81 elements spaced at 5 m, the proposed method can increase the average array gain during course-change maneuvering by about 0.8 dB and lower the average direction estimation error by about 4.7° compared with the original water-pulley model. Using the simulation results to analyze the input sensitivity of the algorithm, the proposed method was simplified to make it easier to implement. Verification using sea trial data shows that the simplified method is feasible and effective.