Manifold inlet of natural gas engine

The utility model relates to a gas inlet manifold for natural gas engine, which is characterized in that a brass sleeve tube is positioned at the connection of a gas nozzle and is pressed into the gas inlet manifold in the interference; the outlet of the sleeve tube is connected with a natural gas guide tube which is connected with the mouth of the inlet valve of the air passage. The utility model has the advantages of avoiding the leakage of the natural gas during the engine operation, reducing the loss of the natural gas, securing the engine to operate normally, lowering the environment pollution and ensuring the ratio of air to gas in the mixed gas to be consistent.