Abstract This paper proposes a home appliance energy efficiency assessment method based on non-intrusive load monitoring (NILM). For the home appliance energy efficiency assessment, firstly, the NILM technology is used to analyze the user side power consumption data, and the power consumption details of the various appliances inside the user’s home are obtained, from which the user’s power consumption characteristics are analyzed. Then, according to the purpose and working mechanism of the electrical appliances, the household electrical appliances are classified, and different energy efficiency evaluation indexes are established according to different types of household electrical appliances. Finally, quantify the less energy-efficient appliances, determine the inefficient running time of the appliance, and calculate the electrical energy lost by the appliance in the corresponding time, and propose targeted power consumption to the user to maximize the user’s power usage behavior. To realize the interaction between the user and the power grid, and greatly improve the user experience.