Lateral flow type well washing drainage oil well pump and using method

According to the lateral flow type well washing drainage oil well pump and the using method, a one-way flow channel is designed in a plunger assembly and used in cooperation with a hollow sucker rod, high-pressure well washing liquid can be pumped into the hollow sucker rod string from the ground, and the well washing liquid flows through a pump cavity and an oil pipe cavity; by means of the structure, pulverized coal, sand grains and dirt deposited on the upper portion of the liquid inlet valve and the inner wall of the oil pipe cavity are taken out of a shaft to the ground together, the purpose of cleaning the pump cavity and the oil pipe cavity without moving a sucker rod string is achieved, the situation that the liquid inlet valve is buried to be invalid or a pump is stuck due to deposition of the pulverized coal, the sand grains or the dirt is prevented, and a coal seam outside the shaft cannot be damaged. The problems that a liquid inlet valve is buried and fails and a plunger is blocked due to deposit