Laser level with automatic locking system and automatic locking method thereof

A laser level (100) with an automatic locking system (80), comprising: a shell, a pendulum body assembly (50) in the shell, and an automatic locking system (80). The pendulum body assembly comprises apendulum body (10) and a supporting subassembly (20) for supporting the pendulum body (10) in the shell which can pivot or swing relative to the shell. The automatic locking system (80) in the shellcomprises a pendulum body lock (70) and an automatic controller (60). The pendulum body lock (70) has a locked state and an unlocked state. In the locked state, the pendulum body lock (70) locks the pendulum body (10) in place and holds it stationary. In the unlocked state, the pendulum body lock (70) allows the pendulum body (10) to move, but when the movement of the pendulum body (10) exceeds apreset limit, the automatic controller (60) will automatically places the pendulum body lock (70) in a locked state. The Laser level with automatic locking system and automatic locking method thereofalso relate to an automatic