Monitoring environment，testing system and other factors will cause noise in the measured seismic wave signal during the monitoring of underwater drilling blasting seismic wave． In order to obtain the real blasting vibra- tion characteristics，the seismic wave signal of underwater drilling blasting was denoised． Firstly，the complementary ensemble empirical mode decomposition was used to decompose the noisy measured seismic wave signal，and the filtering algorithm was established based on the intrinsic mode function obtained from the decomposition． Then，the objective function considering the smoothness of the filtering algorithm and the standard deviation between the filte- ring algorithm and the measured signal was established． The model corresponding to the optimal solution of the objective function was the optimal denoising smooth model of the underwater drilling blasting seismic wave signal． Finally，the denoising ability of the model was analyzed by the denoising error ratio． The results show that the pro- posed optimal denoising smoothness model of seismic wave signal can be used in underwater drilling blasting signal denoising． The model can denoise the original signal while retaining the true components of the original signal．