A method for generating a signal includes: encoding, by an active stylus, transmission information into n-bit q-ary codes; performing, by the active stylus, frequency modulation on the n-bit q-ary codes, respectively, to generate a plurality of encoded frequency-modulated signals; and combining, by the active stylus, a preset fixed-frequency signal for detecting a stylus tip position with the plurality of encoded frequency-modulated signals to form an encoded signal. A method for analyzing a signal, an active stylus, and a touchscreen are also provided. The method for generating a signal, the method for analyzing a signal, the active stylus, and the touchscreen transmit more coding information within a relatively short time, thereby solving a problem of low efficiency of information transmission between an active stylus and a touch screen.