The mobile phone bracket mainly uses the ratchet mechanism. The principle of the ratchet mechanism is that when the rocker of the active part swings counterclockwise, the driving pawl is inserted into the tooth groove of the ratchet, and the ratchet is pushed to turn an angle. At this time, the stop pawl slides on the back of the ratchet. When the rocker of the driving part swings clockwise, the stop pawl prevents the ratchet wheel from rotating clockwise, while the driving pawl can slide over the back of the ratchet tooth, so the ratchet wheel is stationary.