In order to promote the development of Marine Dual Fuel Engine and meet the increasingly stringent emission standards brought by the promulgation of various laws and regulations in the world, this paper summarizes the current development status of Marine Dual Fuel Engine, and analyzes the gas supply technology, combustion technology and injection technology of Wartsila DF dual fuel engine, and analyzes the Gas Valve Unir and Gas Admission Valve in the system It provides a theoretical reference for the development of dual fuel low speed engine.