Key Chain is a project schedule control method proposed by Dr. Goldratt based on constraint theory. It optimizes the project duration by comprehensively considering the relationship between process logic and resource constraints, sets buffer zones to overcome the impact of uncertainties on the project, and monitors the buffer zone to control the project progress in real time, so as to achieve scientific and effective control of project progress. This paper studies the practice of key chains in ship development schedule control, analyzes the problems existing in the current ship development schedule control, and proposes a buffer zone calculation and monitoring method based on risk factors based on ship development characteristics.