The invention provides a deepwater pressure chamber combination experiment device, and belongs to the field of offshore oil engineering. A plurality of connection assemblies with holes are arranged outside the chamber body of the deepwater pressure chamber combination experiment device and are communicated with inside of the chamber body, a guide rail device and a support are arranged in the chamber body, the lower portion of the support is provided with idler wheels rolling on the rail guide device, one end of the inner side of the support is fixedly connected with an actuator and a first fixture in sequence, and the other end of the inner side of the support is fixedly connected with a second fixture. According to the deepwater pressure chamber combination experiment device, a general underwater test platform is built in a laboratory, experiment content and schemes can be set according to different water depth environments, types of underwater equipment and underwater work circumstances, test content standardization of a sensor is achieved on an original structure, the development cycle of the sensor is greatly shortened, and stability of the sensor is improved.