A lock module suitable for being locked to a lock shaft of a portable electronic device is provided. The lock module includes a first lock element and a second lock element. The first lock element includes a first body and a first fastener extending from the first body, and the second lock element includes a second body coupled with the first body and a second fastener extending from the second body. The second fastener and the first fastener are inserted into each other. A limiting space is formed between the first fastener and the second fastener, and the lock shaft is limited in the limiting space.