The invention relates to a high-pressure multi-stage centrifugal pump, which comprises an axial middle-opened shell, a drive shaft, a multi-stage impeller driven by the drive shaft, an inlet ring and a back ring which are arranged on each stage impeller, a sealing bushing on the shell, a seal ring and the like. In the traditional connection mode of the sealing bushing, the seal ring and the shell, radial pin bolts are extended on the lower half part of the shell so as to prevent relative rotation between the sealing bushing or the seal ring and the shell; in order to prevent the sealing bushing and the seal ring from being directly and radially cracked, the radial pin bolts must be small and are easy to cut, but the pin bolts in a such mode do not have sufficient intensity effect, and the sealing bushing and the seal ring can be disassembled only under the condition that a rotation shaft is disassembled; in order to overcome the defect, tangential pin bolts are arranged in pin holes on the shell and contacted with a cutting surface of an outer convex edge of the sealing bushing or the seal ring, and the tail ends of the pin bolts props against and are connected with a cutting boss of the convex edge; and the tangential pin bolts are larger than the radial pin bolts and are compressed instead of being cut, so that an expected loading force can be stood.