The invention discloses a key-free lock. A main body is a square lock box, a die block is fixedly connected with the interior of the lock box, a dovetail groove is designed in the lower portion of the die block, a dovetail nut is placed in the dovetail groove, and moves front and back in the dovetail groove, a thread hole is formed in the middle of the dovetail nut, a code adjusting shaft is screwed into the thread hole, the two ends of the code adjusting shaft penetrate a lock front cylinder and a lock rear cylinder and then are fixedly connected with code adjusting discs, and the code adjusting shaft and the code adjusting discs coaxially rotate; a rack type lock bar is arranged blow the die block in the lock box, a hole is formed in one end of the lock bar, a bar head is arranged at the other end of the lock bar, a screw is inserted in a hole of the lock bar, and the lock bar moves along the smooth end of the screw; a gear is assembled below a lock bar rack, a front handle and a rear handle penetrate the gear to be coaxially connected, and drive the gear to rotate, a convex edge is designed at the bottom of the dovetail nut, a dovetail nut opening groove is formed in the convex edge, a convex edge is manufactured on the ridge back of the lock bar, a starting opening groove and an end opening groove are designed in the convex edge, and the convex edge moves in the opening grooves. The lock trial locking possibility is low, and safety is high.