The utility model provides a larynx area location compresses tightly lock circular knitting machine and constructs accomplishes the location frock through a cylinder, compresses tightly the work piece, pushes away actions such as circle, and the action is in succession, and is efficient, fix a position the frock, promote the module and push away round module including frame, larynx hoop. Larynx hoop location frock includes positioning seat, locating piece and locating piece locating part for clip the larynx hoop. Promoting the module and including driving actuating cylinder, push pedal no. 1,push pedal no. 2, horizontal pole and spring, when driving the actuating cylinder action, directly promoting push pedal no. 1 and advance, the spring is pushed in push pedal no. 1, and spring drive push pedal no. 2 is advanced. The locating piece locating part includes two limiting plates and the stopper that corresponds with spacing recess for fix a position the frock and compress tightly the work piece. Pushing away round module and including leading the nahlock and pushing away the plectane, leading the nahlock and install in push pedal no. 2, push away the plectane and install in push pedal no. 1, when push pedal no. 1 and push pedal no. 2 were god forward, the larynx hoop extended to pushing away the plectane through leading the nahlock, pushed away the plectane and bound round the diameter with the larynx and push away for a short time gradually, up to pushing away full required diameter, accomplished pushing away the circle and move.