The utility model discloses a bus IC card for a subway, which comprises an upper cover and a bottom plate, an NFC coil, a mainboard and an antenna chip are embedded in the middle of the upper cover, and the mainboard and the antenna chip are connected with each other; a drawing sheet is arranged on the bottom plate, a battery and a chip are detachably and fixedly connected to the interior of the drawing sheet, and a battery clamping groove and a chip clamping groove are formed in the positions, corresponding to the battery and the chip, of the middle of the upper cover; a conductive copper sheet is fixedly connected in the battery clamping groove and is connected with the main board; and a signal transmission sheet is arranged in the chip card slot and is connected with the main board. According to the utility model, the signal exchanger is embedded into the bus card on the basis of keeping the functions of the original bus card. Thus, people entering the subway station can be ensuredto carry the exchanger, and meanwhile, the accuracy of passenger flow volume detection is ensured. Moreover, the implementation is not difficult, and only citizens need to replace the bus card.