In a method for unlocking an electronic device, unlocking operation having motion units are preset and are stored into a storage system. Sampled unlocking operation is stored into the storage system. When the electronic device receives a preset unlocking command to start unlocking the electronic device, three-axis acceleration values and three-axis rotation vectors are obtained continuously as an input operation from a first sensor and a second sensor. Motion units of the input operation are recorded. Sampled input operation is obtained by sampling the input operation at a preset time interval. A membership degree of the input operation is calculated. When the membership degree of the input operation conforms to a preset unlocking threshold, the electronic device is unlocked.