A capacitance detection circuit, a touch apparatus, and a terminal device are provided. The capacitance detection circuit includes: a charging circuit, configured to charge a detection capacitor, so that a voltage difference value between two polar plates of the detection capacitor is a first preset voltage value; a discharging circuit, configured to cause the charged detection capacitor to release a first quantity of charges where the first charge quantity is smaller than a charge quantity corresponding to the first preset voltage value; and a signal detection circuit, configured to detect a voltage difference value between a voltage value on the detection capacitor after being discharged by the discharging circuit and a second preset voltage value to determine a capacitance change of the detection capacitor based on the voltage difference value. The capacitance detection circuit is capable of performing capacitance detection when the self-capacitance is large.