To estimate the compensation value reasonably with simulation model under the situation of limited data of proof shooting, the virtual proof shooting method for naval gun considering the reliability of simulation was studied. The adapted weighted Bayesian estimation considering the reliability of simulation was studied. On the one hand, the method for calculating reliability of simulation was analyzed; on the other hand, the adapted weighted Bayesian estimation algorithm considering reliability of simulation was studied. On the basis, considering the principle and requirement of virtual proof shooting, the model for estimating error of firing parameters based on the adapted weighted Bayesian estimation considering reliability of simulation was built. The results from simulation shows that: the adapted weighted Bayesian estimation considering reliability of simulation can verify the reliability of the simulation model efficiently with the test data, thus estimating the target distribution efficiently; the proof shooting method can use the advantages of simulation model and shooting specimen, and realize the reasonably estimation for error of firing parameters, and then, achieve the goal of effectively improving the accuracy of proof shooting.