The utility model provides a valve seat assembly of a plunger pump. The valve seat assembly of the plunger pump is convenient to disassemble, and the reliability of the valve seat assembly is improved. According to the structure of the valve seat assembly of the plunger pump, a valve block is placed on a valve seat, and a spring is placed on the valve block. The valve seat assembly of the plunger pump is characterized in that a buckle cover lid is included, the end edge of the upper surface of the valve seat and the inner side of the lower end edge of the buckle cover lid are provided with a plurality of buckles, the valve seat and the buckle cover lid are assembled into a whole through mutual buckling of the buckles arranged on the valve seat and the buckle cover lid, and the valve block and the spring are contained inside the buckle cover lid.