The invention relates to an underwater hybrid-power robot platform which comprises a housing, a mainframe cabin and a motion control cabin. The outer contour of the housing is in shape of bionic fish,one end of the housing is connected with a bionic fish tail structure, and propellers are arranged on two sides of the housing. The side, close to the front end of the housing, of the mainframe cabinis connected with a camera, and an electronic compass and a controller are arranged in the mainframe cabin. A pitching gravity center adjusting mechanism is installed in the motion control cabin. Thepropellers, the electronic compass and the pitching gravity center adjusting mechanism are electrically connected with a battery cabin. The underwater hybrid-power robot platform adopts the hybrid-power driving design of the propellers and the bionic fish tail structure, and the operating capability of a robot in a complicated ocean current environment is greatly improved. The underwater hybrid-power robot platform can carry multiple types of detection devices, can meet complicated task demands, can performs operations such as water quality extraction, detection and photography, can sample and detect water at different depths through a water pumping cabin and has a wide application prospect.