The invention discloses a bottom hole pressure pump and a pressurizing method thereof, wherein, the pressure pump mainly comprises a filter screen assembly, an upper end connector, a shell, a lower end fastening and an assorted double-channel drill bit. A change valve, a reversing control device, a power cylinder and a pressure cylinder are arranged in the shell sequentially, the lower end of the filter screen assembly is connected with the upper end connector by threads, the lower end of the upper end connector is connected with the shell by threads and sealed, the lower end fastening is connected with the shell by threads and sealed, and the left end of the lower end fastening props against the right end of the pressure cylinder, and presses and connects the change valve, the power cylinder and the pressure cylinder in the shell with a locking part arranged in the upper end connector. The invention can drastically improve the drilling speed, reduce the drilling cost and shorten the drilling period, and has relatively simple structure, short total length, low movement velocity, long service life, low manufacturing cost and high performance-price ratio.