A Shipborne Weapon Device is not only affected by repetitive and low tense bumping impact, but also warship swing and tilt caused by sea wind and wave. To study on the influences in warship mechanical environment on working reliability of shipborne weapon device, the positioning accuracy of a large caliber naval gun rotary magazine is researched. A automated simulation process is carried out in a multidisciplinary design environment. A more accurate surrogate modelling is first set up based on design of experiments technique, and reliability design and optimization are established sequentially, the positioning accuracy reliability of the rotary magazine is increased from 50.2% to 99.3%. In experimental testing phase, the simulation model is verified and corrected based on test data, and the simulation accuracy is ensured, and test limitations are compensated by simulation in addition. This method can promote the work reliability of similar shipborne devices in warship complicated working conditions.