During the fuel supply process, due to the compressibility of the diesel oil and the elasticity of the high-pressure fuel pipe, the high-pressure diesel oil will form pressure fluctuations in the pipe. It takes a certain time for the pressure wave to pass through the pipe, so as to ensure the oil supply interval angle of each cylinder is consistent and oil supply. The quantity is uniform, the diesel engine works smoothly, and the length and diameter of the high-pressure fuel pipe are selected by calculation. Therefore, when a cylinder high pressure oil pipe is damaged, the pipe of standard length and pipe diameter is replaced. In actual use, due to the lack of standard oil pipes, other oil pipes are used instead, regardless of the length of the oil pipe and the same pipe diameter, so that the length of the oil pipe and the pipe diameter are very different. Although it can be used in an emergency, it will lead to the oil supply of the oil pipe. The advance angle and the amount of oil supply change, which makes the whole machine work unevenly. Therefore, the standard high-pressure oil pipe must be used in use.