The invention discloses a load smooth control method based on a demand side resource unified state model. Firstly the demand side resource unified state model is established, and then load curve smooth control is realized based on the model. The response characteristics of different types of demand side resources can be described by using a unified mathematical expression by the unified state model; a control matrix is derived to realize real-time management and control of the demand side resource output power on the basis of considering the response order of the demand side resources; fully consumption and absorption of renewable energy sources can be realized by a control strategy on the basis of considering the energy using comfort level of the user so that the SOC before traveling of the electric automobile is ensured to meet the user requirements, and the indoor temperature in which the temperature control load is located is ensured to meet the comfort requirements of the user; and power fluctuation of the load can be obviously reduced by the control, and the power fluctuation rate can be maintained to be below 10% of the preset value.