The power supply side regulating capability of the power grid is limited, and it is important to dig deep into the load side regulation capability. Electro-heating load is a time-shifting load with the characteristics of small thermal inertia, fast response, high controllability, etc. It has the potential to participate in active power dispatching and control the power grid. When the electro-heating load is working, the indoor temperature curve is affected by many factors. It has a similar influence characteristic quantity, and a similar temperature rise and fall process is exhibited in the temparature setted range. When using the traditional equivalent thermal parameter to evaluate, the outdoor temperature at the end of the warming up or cooling down process is unknown, so the regulating potential of individual electro-heating load cannot be accurately evaluated. Therefore, this paper proposes a similarity-based support vector machine single electro-heating regulating potential evaluation method, and compared with the traditional equivalent thermodynamic model, it shows that this method has higher evaluation accuracy.