The invention discloses a twist drill for machining stainless steel. The twist drill for machining the stainless steel comprises a shell. The bottoms of the two sides of the shell are both fixedly connected with clamping plates. The clamping plates are provided with clamping grooves. The two sides of an inner cavity of the shell are both fixedly connected with sliding rails. Sliding grooves are formed on the inner side of the sliding rails. The top of the shell fixedly communicate with a threaded pipe. The top of the threaded pipe is provided with a threaded cover. The top of the threaded cover is provided with a first through hole. A limiting plate is arranged in an inner cavity of the threaded cover. When a twist drill body is used and bears a large pressure, the twist drill body can gradually retract into the inner cavity of the shell according to the magnitude of the pressure, and a damping spring achieves the damping function and the supporting function; and in this way, it is avoided that the twist drill body is damaged by large pressure, the service life of the twist drill body is prolonged, and the economic loss of a user is reduced. The twist drill for machining the stainless steel is simple in structure, convenient to operate, remarkable in practical effect and worthy of popularization.