Embodiments of this application provide an envelope tracking modulator, comprising: a linear amplification circuit, a coupling capacitor, a buck circuit, a circuit sensor, and an offset current generation circuit. An output end of the linear amplification circuit is coupled to a first end of the coupling capacitor, and a second end of the coupling capacitor is coupled to a power supply node. The offset current generation circuit is coupled to the first end and the second end of the coupling capacitor, and the offset current generation circuit is further coupled to a control end of the buck circuit. An input end of the circuit sensor is coupled to a line between the output end of the linear amplification circuit and the first end of the coupling capacitor, and an output end of the circuit sensor is coupled to the control end of the buck circuit.