According to new requirements on the scheduled maintenance for warships due to the mission expansion of warships and the development of equipment technology under the new situation，the research on the reform of scheduled maintenance mode was carried out. The general idea that transforming the time-based maintenance to the combination of time-based and condition-based one was presented. The key problems including the reasonable determination for the maintenance classification，time，project scope，and project duration were studied intensively. Some supporting mechanisms，such as ship underwater hull cleaning mechanism，the main onboard machinery replacing maintenance mechanism，and the mechanism determining the repair demands based on the status monitoring，were discussed. Some pilot projects for some representative warships were carried out. The practice shows that the theoretic readiness ratio for warship in the new scheduled maintenance mode can be improved about 5 %，and the benefit is very obvious.