A high-pressure cleaning machine uses water as the working medium and consists of two main parts: a booster pump and a power drive unit. Usually, the power drive pump completes a suction and discharge process on the water, converting ordinary water into high-pressure and low flow rate water, and then delivering it to the high-pressure pipeline to reach the high-pressure nozzle with a certain amount of energy. The aperture of the high-pressure nozzle is much smaller than the diameter of the high-pressure pipeline, so the water reaching the high-pressure nozzle needs to be accelerated in order to pass through the nozzle.

In this way, the nozzle can convert high-pressure and low-speed water into low-pressure and high-speed jets. There are three ways to control the water flow rate: by increasing or decreasing the inner diameter of the pump head, and by lengthening or shortening the stroke of the plunger. By increasing or decreasing the reciprocating speed of the plunger.

The vast majority of high-pressure cleaning machines use a system consisting of a valve and a pump head. The plunger pulls water into the inlet valve and pressurizes it to pass through the outlet valve. Valves control water flow through pumps by preventing backflow. The valve is composed of springs and brackets, and pressure operation is completed due to the different pressure differences on both sides of the valve. When the pressure acting on the valve exceeds the capacity of the spring, the valve opens. During the opposite stroke, water will automatically push the bracket onto the valve seat, keeping the valve closed and preventing backflow.

The high-pressure water jet sprayed tangentially or positively impacts the surface of the cleaned object (workpiece), which is called jet operation. High pressure water jet is a simple form of energy conversion and application. When the impact force of high-pressure water jet is greater than the adhesion between dirt and the surface of the object, it will peel off and wash away the dirt, achieving a cleaning device for cleaning the surface of the object.

High pressure cleaning machines are widely recognized as one of the most scientific, economical, and environmentally friendly cleaning methods in the world because they use high-pressure water columns to clean dirt.