A steel wire self-locking mechanism and a lifting device are provided. The steel wire self-locking mechanism includes a surrounding plate and a self-locking gear and a locking device arranged in the surrounding plate, and uses a friction force of a threaded sleeve to lock the lifting device. The lifting device includes a lifting assembly and a beam assembly. The steel wire self-locking mechanism is arranged in the beam assembly, and the locking of the lifting device is realized by the steel wire self-locking mechanism. The steel wire self-locking mechanism and the lifting device have good adaptability. Due to a smaller volume, the steel wire self-locking mechanism is applicable to lifting tables in various sizes.