The harmonic balance method is one of the computational methods in frequency domain with a high computational efficiency, which has won special attention in present numerical studies of unsteady flow, and it has an obvious advantage especially for periodic unsteady flow problems. A harmonic balance method was used to simulate the forced pitching oscillation of the HBS(hyper ballistic shape) in different conditions, and then the coefficient of force and moment versus angle of attack were rebuilt. A comparison was made with the time domain method to investigate the performance of the harmonic balance method. Results show that the harmonic balance method is applicable to simulate middle and small amplitude pitching, and the computing time won’t be effected by the frequency. Therefore, the harmonic balance method has obvious advantage for problems with a long period.