The invention discloses an underwater screw propeller propelling module, which comprises a servo motor and a speed reducer connected with a tail cone, wherein the speed reducer is fixedly connected with the inside of the tail cone and is connected with a driven shaft passing through a bearing support through a shaft coupling, and the driven shaft is provided with a screw propeller; the shaft coupling is a magnetic shaft coupling consisting of an inner hub, an outer hub sleeved outside the inner hub, a stainless steel isolation cover arranged between the inner hub and the outer hub, and a clamp ring fixedly connected with the stainless steel isolation cover; and the outer hub is arranged on an output shaft of the speed reducer, the inner hub is arranged on the driven shaft, and the clamp ring is fixedly arranged in the tail cone. The invention also discloses an underwater vehicle comprising the underwater screw propeller propelling module. The underwater screw propeller propelling module adopts a magnetic coupling technique to realize power transmission, adopts the isolation cover to isolate water from a sealed cabin, adopts a corrosion resistant material and a ceramic bearing to solve the problem of aqueous corrosion resistance, adopts the modularization design to make the structure compact and easy to replace, dismount and mount, and achieves the absolute sealing between a pressure resistant cabin of the underwater vehicle and the external sea water.