The portable foam sprayer is an accessory of a high-pressure cleaner and is widely used for washing cars and equipment. It uses the high-pressure water flow from the high-pressure cleaner to suck detergent from the bottle below the foam sprayer through the siphon principle, mix it with the high-pressure water, and form a cleaning mixture. After passing through the foamer, the mixture is turned into rich and delicate foam, which is sprayed onto the surface of the object to be cleaned, adsorbed on the surface to be cleaned, dissolves oil stains and dirt, greatly improves the cleaning quality, and thoroughly removes dirt. It is simple and convenient to use. Only one high-pressure cleaner is needed to achieve the decontamination and cleaning functions without the need for additional equipment. It is particularly suitable for outdoor use, easy to carry, and simple to operate. It is the choice for cleaning household vehicles.