The invention provides an earth-excavating device and earth-excavating method for earth pressure balance shield or pipe-jacking construction. The earth-excavating device comprises a mud pressing pumpconnected to a shield or a screw conveyor earth discharge mouth of a jacking pipe; a booster pump located in the shield or a last-section frame of the jacking pipe and connected with the mud pressingpump through a first pumping pipeline; a wellhead pump located at a tunnel wellhead and connected with the booster pump through a telescopic pipeline; a ground earth collecting pit connected with thewellhead pump through a second pumping pipeline. The earth-excavating device is specially used for tunnel construction by means of a shield or jacking pipe method. By means of the mud pressing pump arranged at the screw conveyor earth discharge mouth, the booster pump arranged in the shield or the last-section frame of the jacking pipe, and the wellhead pump arranged in the tunnel wellhead, the screw conveyor excavated earth generated from the shield or the jacking pipe during the excavation process is continuously and rapidly pumped until the earth is pumped into the ground earth collecting pit, the booster pump is connected with the screw conveyor earth discharge mouth in a sealed mode, and the screw conveyor excavated earth is extruded into pumps in a sealed mode and then into pumping lines, so that the pumping efficiency is higher.