This application provides a load line circuit and an electronic device, where the load line circuit is applied to the electronic device. A voltage value of a feedback voltage provided by the load line circuit to a switch-mode power supply is linearly and positively correlated with each of a voltage value of a first voltage and a current value of a first current, where the first voltage is a voltage provided to a load circuit, and the first current is a current provided to the load circuit. Through disposition of the load line circuit, the switch-mode power supply can implement a load line function.