Abstract: Based on the schedule management for the first reactor of advanced passive pressurized water reactor（AP1000）, this paper states the major problems under the complicated contractual relationships, focusing on the design of first reactor and the first-time manufacture of primary equipment as well as the modular construction, combined with the actual situation of Sanmen nuclear power project construction, and discusses and analyzes the major challenges and difficulties that the first AP1000 nuclear island design imposed on the scheduling management. A series of countermeasures is taken to minimize the impact on schedule delay of the design of first reactor. It also intends to put forward, in view of the experience and lessons learned in Sanmen nuclear power project construction, some suggestions for the schedule management of the future AP1000 projects.