A detachable entrance and exit gate with a combined commodity burglarproofing and small arms detecting system including a detachable entrance and exit gate with a pair of vertical type panels which are oppositely disposed inside of an entrance and exit door, a central processing unit connected with the transmitting and receiving signal frequency coil portions, an image-receiving device, a warning flare and a photographing device which are controlled by a central processing unit, where the small arms detecting transmitting coil portion and the commodity burglarproofing transmitting coil portion are interiorly installed at one side of the vertical type panel of the entrance and exit gate and the small arms detecting receiving coil portion and the commodity burglarproofing receiving coil portion RX2 are interiorly installed at one side of the other vertical type panel of the entrance and exit gate, so that a variation existing between a frequency zone of the small arms detecting transmitting and receiving coil portions and a frequency zone of the commodity burglarproofing transmitting and receiver coil portions can be largely established, thereby resulting in no mutual interference.