The invention discloses a coin separating device comprising a driving mechanism; a housing; a coin screening mechanism, a coin separating mechanism, and a coin collecting mechanism, which are disposed in the housing. The top part of the housing is provided with a coin inlet, and the coin screening mechanism is disposed on the lower part of the coin inlet. The coin separating mechanism is disposed on the lower part of the coin screening mechanism, and the coin collecting mechanism is disposed on the lower part of the coin separating mechanism. The coin screening mechanism and the coin separating mechanism are respectively connected with the driving mechanism. The driving mechanism comprises a single-chip microcomputer, a motor, a belt pulley. The single-chip microcomputer is connected with the motor, and the motor is connected with the belt pulley. The coin separating device has advantages of simple structure, reasonable device, low production cost, and ability of separating the coins with banknotes quickly.