The invention relates to a small-sized and multipurpose high-pressure pump. The small-sized and multipurpose high-pressure pump is composed of a power end and a hydraulic end, wherein the power end comprises a crank case, a back cover, a crankshaft, a crankshaft end cover, a plurality of connecting rods and an integrated intermediate rod; the hydraulic end comprises a pump head, a plurality of intake valves and a plurality of drain valves. The small-sized and multipurpose high-pressure pump has the following advantages: because the original crosshead and plunger rod are replaced by the integrated intermediate rod, the coaxiality is good, assembly is convenient, and meanwhile, the size of the product can be reduced; the crank case and the back cover are provided with fins, the crankshaft end cover is provided with heat-dissipating holes, meanwhile, the part of the crank case, which corresponds to the heat-dissipating holes, is provided with slots, moreover, the middle of the bottom of the crank case is sunken upwardly, consequently, the coercive measures can ensure that the heat in the crank case can be dissipated out as soon as possible, so that the lubricating property of the lubricating oil in the crank case cannot be affected, as a result, the parts in the crank case can be prevented from being abraded, and thereby the service life of the entire product can be prolonged. The arrangement of the fins also can play a reinforcing role at the same time.