In deep-sea drilling, deepwater instruments’ water tightness and pressure resistance should be verified by pressure simulation testing system before launched. So deepwater pressure simulation testing system is often used. This article improves the traditional deepwater pressure simulation testing system, the improved system"s electrical control part is mainly composed of King View and PLC. The system uses PLC as the lower computer, and through its built-in A/D module, combined with pressure sensors, it can collect pressure signals. Users can set parameters and preset programs, and control the on-off of the pump and the valves through digital outputs, contactors, etc. The system provides auto-manual dual-mode. By combining the PLC serial port with the Bluetooth serial port transmission module, remote device display can be achieved. KingView was developed as the upper computer, to communicate with the lower computer via serial port based on Modbus RTU protocol, develops a human-machine interaction interface through configuration programming, realizes pressurization, pressure holding, and unloading setting for the entire process of pressure simulation testing, as well as monitoring the testing process, displaying pressure curves, and reporting forms. The deepwater pressure simulation testing system has the advantages of friendly Human-Machine interface, intuitive simulation monitoring, complete functions, reliable performance, convenient operation, safety, and scalability.