A method for controlling earphone switching, an earphone, and an earphone system are provided. The method includes the following. A first earphone determines whether the first earphone is switched to a non-wearing state from a wearing state. The first earphone is coupled with a second earphone and an electronic device and serves as a master earphone, and the second earphone serves as a slave earphone. When the first earphone is determined to be switched to the non-wearing state from the wearing state, the first earphone switches the first earphone to serve as the slave earphone and the first earphone switches the second earphone to serve as the master earphone. Switching between master and slave earphones can be achieved according to changes between the wearing state and the non-wearing state of the master earphone, such that user experience can be improved.