Listing of Claims: 1. A large-flow

Listing of Claims: 1. 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. 2. The large-flow plunger pump according to claim 1, further comprising crankshaft support roller assemblies mounted on a periphery of a crank of a crankshaft of the crank-link mechanism; each of the crankshaft support roller assemblies comprises a roller and a fixed mount; a gap between each of the plurality of rollers and the crank is adjustable; and each of the plurality of rollers is arranged on the fixed mount and the fixed mount is fixed on the box. 3. The large-flow plunger pump according to claim 2, wherein the gap between the rollers and the crank is adjusted by adjusting screws. 4. The large-flow plunger pump according to claim 1, further comprising a suction-pressure stabilizer which is, having a cooling water coil therein, provided at a suction inlet of the plunger pump. 5. The large-flow plunger pump according to claim 4, wherein a circulating cooling water inlet at one end of the cooling water coil is communicated with a water replenishing device via a pipeline while the other end of the cooling water coil is communicated with a cooling water inlet of a plunger pump oil pool cooling coil, a high-temperature water outlet is communicated with a domestic heat supply pipeline, and the domestic heat supply pipeline is communicated with the water replenishing device.