The existing photo-electro-thermal theory and models of LED are analyzed. Based on the model proposed by Hui et al., combining mathematical derivations, simulations and experiments, a linear relationship between the positive input current and input power is studied when the LED package module is at a constant temperature of heatsink. From the circuit control strategy, a novel photo-electro-thermal LED model with simplified variables is proposed. The temperature of heatsink and input current are the two variables of this model, which are easy to measure and control. The feasibility of the proposed model is verified by optical experiments on two typical LED package modules. Compared with the model proposed by Hui et al., the model is simple and convenient to perform circuit drive control. It is helpful for the design of the LED lighting system and the establishment of LED drive power control strategy with excellent optical properties, providing a theoretical basis for LED dimmer control technology.