A redundant Field Programmable Gate Array (FPGA) based controller for subsea Blow-Out Preventer (BOP) is presented. Triple modular redundancy technique is used for architecture design, since high reliability is a necessary requirement for subsea BOP control system. A multiprocessor system is developed to enhance reliability of the processors and performance of the system. In addition, the shared memory method is applied to interchange information between the processors. One processor is responsible for communication, while the others run application programs.