Bipolar area DC protection system malfunction will lead to serious consequences bipolar forced block, so it is important to improve bipolar DC protection system reliability. This paper analyzes two configuration strategies of UHVDC bipolar area DC protection system, establishes a reliability model of the configuration strategy, and derives its reliability formula and reliability graphs. The results show that the protection system integrated into a triple of configuring cubicles has greater reliability. It describes the bipolar protection functions and action strategies, analyzes bipolar neutral bus differential protection, NBSF sequence logic and metal loops enable signal and other key technical problems and then proposes the optimization strategy. At present, part of the optimization program is implemented in multiple UHVDC power transmission system, and then system operates well after adopting the measure. The latest optimization program will be implemented in the new project.