Abstract: Disclosed are a tandem modulation device fan and a control method thereof. The tandem modulation device fan comprises a frame, fan blades disposed in the frame, and a light-emitting module disposed in the frame. Two corresponding sides of the frame are each provided with a circuit board and a pin structure. Pins and the circuit boards on the two sides can automatically switch and recognize inputs and outputs irrespective of the polarity. The two sides, provided with the circuit boards, of the frame are each provided with a magnet for magnetic connection with the frame of an adjacent fan. The circuit board is electrically connected to a master controller. Fans are connected end-to-end through attraction of magnets, such that the electrical conductivity is improved, and the service life is prolonged.