SUMMARYAn objective of the present invention is to provide a large-flow plunger pump in which, by providing assemblies such as a detachable upper crosshead guide, an intelligent plunger packing lubrication system and crankshaft support roller assemblies, it is convenient for the maintenance of quick-wear parts, the friction coefficient of the plunger packing is decreased, the multi-cylinder multi-support of the crankshaft is fulfilled, the reliability of the crankshaft is significantly improved, and the service life of large-flow plunger pumps is prolonged overall. Thus, such a large-flow plunger pump is efficient and energy-saving.For this purpose, the present invention employs the following technical solutions.The present invention provides a large-flow plunger pump, comprising a box, a crank-link mechanism, a crosshead, a plurality of plungers, a suction valve and a discharge valve; the crank-link mechanism drives the plurality of plungers to do reciprocating motion; a crosshead guide hole comprises a detachable upper crosshead guide and a lower crosshead guide located on an inner surface of the box, the detachable upper crosshead guide being connected to the lower crosshead guide via positioning pins and fixing bolts; on each of the plurality of plungers, a plunger packing lubrication system is provided, which supplies lubrication oil to each of the plurality of plungers by a multi-point lubrication oil pump via a check valve and a pressure sensor, a high-pressure lubrication oil pump of the multi-point lubrication oil pump supplies lubrication oil to a plurality of plunger packing sets separately via a plurality of lubrication oil pipes; and, both the suction valve and the discharge valve are damping valves, each of the damping valves comprises a damping ring which is provided between a valve plate integrally vulcanized with the damping ring and a valve seat, and a volume cavity which is communicated with a valve chamber via pores on the valve plate is formed within the damping ring.