High-pressure plunger pumps are widely used in industrial applications because of their high efficiency and reliability. The common faults of mechanical， hydraulic and electrical systems of high-pressure plunger pump are discussed， and the repair and renovation technology of each part are elaborated， including the repair of piston and cylinder block， the renovation of valve， the upgrading of sealing technology and the modernization of control system. Through the application of these technologies， the performance and service life of the pump are significantly improved， and comprehensive technical guidance for the optimization and maintenance of high-pressure piston pumps is provided.