A capacitance detecting circuit includes induction units; a transferring capacitor configured to transfer charges to a capacitor of a scanned induction unit; a charging module that charges the transferring capacitor, wherein a first terminal of the charging module connects to the first terminal of the transferring capacitor, and a second terminal of the charging module connects to a first power supply; a discharging module that discharges the transferring capacitor and including a first resistor and a second switch; and a controller connected to the charging module, the transferring capacitor and the discharging module, and configured to control the second switch to switch on when a voltage of the transferring capacitor is larger than a preset threshold voltage, and to update a count value and detect a touch on the induction units according to the count value.