Natural gas supply device of engine

The invention belongs to the technical field of engine natural gas system fixing, and particularly relates to a natural gas system fixing frame based on an engine cylinder cover. The natural gas system fixing frame comprises a double-wall supporting pipe, the double-wall supporting pipe is fixedly connected with a natural gas inlet channel of the cylinder cover, and a natural gas injection valve is arranged at the upper end of the double-wall supporting pipe; a double-wall corrugated pipe is arranged at the upper end of the natural gas injection valve, a double-wall air supply pipe is arranged at the upper end of the double-wall corrugated pipe, the double-wall supporting pipe comprises an air cavity between the double walls, the double-wall corrugated pipe comprises an air cavity between the double walls, and the double-wall air supply pipe comprises an air cavity between the double walls; and the cylinder cover is further provided with a pressurized air inlet channel, the pressurized air inlet channel is co