To explore the deformation law of offshore pile foundation under long-term horizontal circulating load, the paper chose medium sand as test soil and carried out model test under effect of horizontal circulating load,and got the circulation weakening law of pile top displacement cycle under effect of different load forces and frequencies of high order circulating load. The results show that the impact of cyclic times and loading forces on displacement variation is obvious.When the frequency is not changed,the more the loading force,the more is its displacement under effect of horizontal circulating load.The change of frequency has little influence on pile-top displacement. The change of hysteresis loop of pile top mainly occurs in the first 10,000 rounds of cyclic loading and then gets stable. The results can provide valuable reference for ensuring the reliability of offshore pile foundation.