A marine LNG-diesel oil dual-fuel engine module type gas supply device is composed of a gas bag 1, gas inlet hoses 2 and gas supply modules 3, and is characterized in that gas supply branches are divided from the gas bag and connected with the gas supply modules 3 so that gas can be directly supplied to an engine gas inlet pipe; and the invention belongs to the technical field of marine diesel engine energy refitting and refitting from single diesel oil fuel power to LNG-diesel oil dual-fuel power, and particularly relates to the marine engine natural gas modularized gas inlet device. According to the principle, gasified pure natural gas enters the gas bag through a gas inlet pipeline firstly and enters the single gas supply modules from the gas bag through the braches; each gas supply module is an independent part and comprises an installation plate, a jet valve and a natural gas spray nozzle; the gas supply modules are arranged on a shell of the engine gas inlet pipe; the installation stability is ensured, and meanwhile the natural gas spray nozzles can accurately jet the natural gas into engine gas intake manifolds; and the number of the gas supply modules is freely configured according to the gas inlet amount of an engine and the number of the gas intake manifolds. The marine LNG-diesel oil dual-fuel engine module type gas supply device has the beneficial effects that installation is easy, use is convenient, and the gas intake amount of all the gas intake manifolds is reasonably distributed while the gas intake stability is ensured.