Unlocking system and method for portable electronic device

The invention relates to an unlocking method for a portable electronic device. The method comprises the following steps of: sensing, namely sensing the rotary direction and rotary angle of the portable electronic device continuously by using a gyroscope; acquiring, namely storing the rotary direction and the rotary angle in a storer; finishing judgment, namely if the rotary direction and the rotary angle which are stored in the storer are changed within preset time, returning to the sensing step, and if the rotary direction and the rotary angle are not changed within the preset time, performing an unlocking judgment step; judging unlocking, namely comparing the rotary direction and the rotary angle in the storer with the rotary direction and rotary angle of preset unlocking operation, if so, performing an unlocking step, otherwise, returning to the sensing step; and unlocking, namely unlocking the portable electronic device. The invention also provides an unlocking system for the portable electronic device. B