Aiming at the base models of bow winch and stern windlass of 4500 tons tanker, according to the relevant specifications of China Classification Society, the static analysis module of ANSYS software is used to check the structural strength of windlass and windlass, and the results are analyzed. In addition, topology optimization idea is introduced into the structural design process of windlass winch base, and topology optimization module in ANSYS software is used to carry out structural lightweight topology optimization design of windlass winch base. The results show that the base structure of windlass winch meets the design requirements under the conditions of wave load on deck, 45% broken load of windlass and 80% broken load of main chain, and the maximum stress is in the contact part between the base and the hull, so special attention should be paid to the design and installation. Under the condition of ensuring the structural stiffness and strength, the base structure after topology optimization meets the design requirements, and its mass is reduced by 20%.