Parasitic high-pressure common-rail pump

A parasitic high-pressure common-rail pump comprises a pump body, one or more oil pump system assemblies, one or more roller bodies, an oil outlet pipeline and an oil overflow pipeline, wherein the oil pump system assemblies are arranged in the pump body; the transmission ends of the oil pump system assemblies extend out of the pump body, and are connected with the upper end of the roller bodies; the roller bodies are positioned outside the pump body; the oil outlet pipeline and the oil overflow pipeline are arranged in the pump body; the oil outlet pipeline is used for connecting an oil inlet in the pump body and oil outlets in the oil pump system assemblies; the oil overflow pipeline is used for connecting oil overflow openings in the oil pump system assemblies and an oil return opening in the pump body. According to the benefits, the novel parasitic high-pressure common-rail pump provided by the invention is small in size and relatively light in weight, has a relatively high degree of freedom when being combined with other equipment, and is particularly suitable for being added on a small-sized device.