A lock device (30) is disclosed, which comprises: a holder (31) which is provided with a through hole (312) running through the holder (31) and a slide (311) intersecting with the through hole (312); a guide bar (32), which is provided with an outer threaded area on at least a portion of a surface and passes through the through hole (312), where the outer threaded area is located at where the through hole (312) intersects with the slide (311); a lock component (35) received in the slide (311), where the end of the lock component (35) facing towards the guide bar (32) is provided with a lock threaded area which can engage with the outer threaded area of the guide bar (32); and a drive assembly which drives the lock assembly to move towards or away from the guide bar (32) in the slide (311). In the embodiments of present disclosure, the guide bar is locked when threads on the lock threaded area engage with outer threads on the outer threaded area. The lock devices according present disclosure are simple, easy to maintain, low cost, not ease to failure, with high reliability and able to bear very large load. In addition, they will not generate noise and need not to be operated with electricity, and the operation is more convenient.