Some embodiments of the invention provide an active pen, a boost circuit and a control method thereof. The boost circuit comprises an inductor, a switch module, a capacitor and a control module; The switch module at least comprises a first switch and a second switch, and the capacitor is connected with the second switch in parallel; Wherein the first end of the first switch is connected to one endof the inductor, the second end of the first switch is connected to the first end of the second switch, and the second end of the second switch is grounded; The other end of the inductor is connectedwith a power supply; The control module is connected to the control end of the switch module; And the control module is used for controlling the state of each switch in the switch module, so that thefirst end of the second switch outputs a voltage signal with preset frequency and amplitude. By adopting the embodiment of the invention, the signal-to-noise ratio of the communication signal can beimproved by using the frequency hopping communication technology, and meanwhile, the system power consumption can be reduced by adjusting the coding voltage amplitude according to the application scene.