Abstract: In order to solve the problems of system backwardness, long operation time, insufficient emergency response ability, and low redundancy in the BOP control system of deep-water semi-submersible platform, this article starts from the ground control and underwater control system of BOP of deep-water semi-submersible drilling platform, and analyze the characteristics of the BOP control system of the ultra-deep water semi-submersible drilling platform. Meanwhile, by combining with the actual field operation experience and requirements, the paper discusses the appropriate modification and upgradation methods for the ground & underwater BOP control system of current deep-water semi-submersible drilling platform. Inspite of a small investment, it is hoped that the purpose of rapidly upgrading the BOP control system can be achieved with stable and safe operation of the underwater BOP. Finally, an improved and upgraded method is proposed, which can provide reference for the control system upgradation of the BOP of deep-water semi-submersible drilling platform in future.