The invention relates to a floating type hinge device of a screw conveyer. The floating type hinge device comprises a front groove body arranged on a screw conveyer body in a sleeving manner, a sleevearranged on the front groove body in a sleeving manner and a connecting rod for movably connecting the front groove body with the sleeve; the front groove body is fixedly connected with the screw conveyer body, the sleeve is fixedly connected with an anterior shield of a shield tunneling machine, a sealing structure is fixedly arranged on the end face, far away from the anterior shield of the shield tunneling machine, on the sleeve, and a gap between the sleeve and the front groove body is sealed through the sealing structure; and movable connection of the connecting rod enables the front groove body and the sleeve to be capable of achieving relative motion so as to adapt to the working condition of turning of the shield tunneling machine. A new hinge manner is provided, and the beneficial effects of the simple structure and low cost are achieved. When the shield tunneling machine makes a turn, the sleeve and the front groove body are connected through the connecting rod to form the hinge device, the sensitivity of the screw conveyer is increased, and the screw conveyer can be suitable for the working condition of small radius turning of the shield tunneling machine.