The invention relates to a resident load demand response potential evaluation method based on a flexibility index. The method comprises the following steps of determining flexibility of a resident load; and according to the flexibility of the resident load, evaluating a demand response potential of the resident load. By using the resident load demand response potential evaluation method based on the flexibility index, through calculating a potential of a rapid response type load in residents, flexibility and sustainable response time and timely grasping a rapid demand response potential of an internal load, power grid dispatching operation is participated in based on that so as to solve a problem that a conventional power supply adjusting capability during a real-time phase is insufficient.