Auxiliary installation system and installation method of ocean engineering underwater propeller

The invention discloses an auxiliary installation system and an installation method of an ocean engineering underwater propeller. Two winches are arranged on a floater or deck of the ocean engineering; one of the winches, namely the first winch, is used for controlling up and down movement of the propeller, and the other winch, namely the second winch, is used for controlling horizontal and vertical movement of the propeller. The overall movement of the propeller is completed within a support and guide frame. In installation of the underwater propeller, the support and guide frame is installed to the floater (deck) and a seat area of the propeller in advance; the process is performed before the launching and undocking of the ocean engineering so that time and difficulty of the subsequent installation are reduced. By the auxiliary installation system and the installation method, limit of the water depth in the installation area can be decreased to the underwater propeller, the propeller can be placed in the installation area in advance when in a shipyard, and then moved to the installation area along with the platform, so that installation requirements of the propeller to auxiliary working ships are lowered and installation cost of the underwater propeller is reduced.