The invention relates to an electromotor combined with a pressure vessel. The electromotor comprises an electromotor shell, a rotating shaft, a stator, a rotor, a shaft extension end cover, a non-shaft extension end cover, a terminal box, a terminal box cover, a terminal board and electric connection components, wherein the terminal board and the electric connection components are arranged in the terminal box, and connection components are arranged at the two ends of the electromotor shell. The electromotor is characterized in that a bearing hole in the non-extension shaft end cover does not penetrate through the outer end face, a shaft sleeve is fixed to the outer end face of the shaft extension end cover in a sealed mode, a flange is fixed to the other end of the shaft sleeve in a sealed mode, the shaft extension end of the rotating shaft penetrates through the shaft extension end cover and the shaft sleeve and extends out of the flange, sealing elements are arranged between the connection components of the shaft extension end cover, the non-shaft extension end cover and the electromotor shell, and a sealing element is arranged between the terminal board and the terminal box. The rotating shaft of the electromotor is used as the rotating shaft of a stirrer of the pressure vessel, the pressure in the pressure vessel shifts into the electromotor through the shaft sleeve, and the problem that the pressure vessel is difficult to seal is well solved through the good sealing performance of the electromotor shell and all the components. The electromotor is suitable for high-pressure operation environments.