A touch terminal, an active stylus detection method, and a system are disclosed. The method includes the following steps: separately scanning, by a touch screen controller, multiple pieces of noise information on multiple operating frequencies of an active stylus of a touch screen; determining, by the touch screen controller, a target operating frequency according to the multiple pieces of noise information; and sending, by the touch screen controller, the target operating frequency to the active stylus, and adjusting an operating frequency of the active stylus to the target operating frequency, so that the active stylus and the touch screen operate jointly at the target operating frequency. In the method, the touch screen controller scans noise information on multiple operating frequencies of the active stylus, so as to determine a target operating frequency of the active stylus, so that the active stylus operates at the target operating frequency.