The fine content of fine sand will have a great impact on the reinforcement effect of the dynamic compaction method when treating the silty fine sand foundation by the dynamic compaction method. Aiming at the problem of the influence of fine content in silty fine sand on dynamic compaction reinforcement effect，we study the applicability of dynamic compaction method with different fine content of silty sand，obtain the influence of fine particle content on dynamic compaction settlement，excess pore water pressure and reinforcement effect by the model test in the laboratory，and put forward the corresponding construction suggestions. The results show that the fine content has much influence on the effect of dynamic consolidation of homogeneous silty fine sand. Ten percent of the fine particle content is the turning point. When the content of fine particles is more than 10%，the higher the content of fine particles is ，the lower the applicability of the dynamic compaction method is.