Based on the reliability theory, this paper analyzes sea wall overtopping reliability under the condition of overtopping allowed and establishes the limit state function for sea wall overtopping. The overtopping failure probability and reliability index of a sloping sea wall in Qingdao are calculated using Monte Carlo simulation method and taking the significant wave height and the spectrum peak period as variables. The significant wave height and the spectrum peak period are fitted using Log-normal fitting and Gumbel fitting. The Log-normal fitting is adopted according to the fitting results. It is concluded that sea wall overtopping reliability analysis is feasible, the probabilistic meaning of the sea wall overtopping reliability index is definite, and the sea wall overtopping reliability index is more reasonable than the standard of the tolerable overtopping limits.