Electronic cigarette and power supply thereof

The utility model discloses an electronic cigarette and a power supply thereof. The power supply comprises an outer shell, a cell, a control board, a voltage output head and a button. The cell and the control board are arranged in the outer shell. The voltage output head is arranged at one end of the outer shell. A pressing switch is arranged on the control board and sleeved with a voltage regulator. A first through hole is formed in the position, corresponding to the voltage regulator, of the side wall of the outer shell. The button penetrates through the first through hole and is sleeved with the voltage regulator in a penetrating mode, and the pressing switch is turned on or turned off through pressing. The button is coaxial with the voltage regulator and drives the voltage regulator to rotate when rotating; or a gap is formed between the button and the voltage regulator, the voltage regulator penetrates through the first through hole and protrudes out of the outer side wall of the outer shell, and the height of the portion, protruding out of the outer side wall of the outer shell, of the voltage regulator is smaller than or equal to the height of the portion, protruding out of the outer side wall of the outer shell, of the button. The electronic cigarette can be conveniently operated by a user with one hand, and is simple in structure and convenient to operate.