The invention discloses a resident load participation system peak load regulating potential calculating method, and the method can calculate the peak load regulating potential according to a sequence from bottom to top; the method can obtain the user peak load regulating potential from three aspects, respectively referring a user type peak period mean power APL, a demand response participating peak period power average reduction rate PRR, and a demand response participating user number DRPN. The specific method can be expressed as PLPct, n, j, T=APLct, n, j, T.PRRct, n.DRPNct, n. The resident load participation system peak load regulating potential calculating method can execute peak price in the power consumption peak, thus effectively reducing system peak; the method can simply and efficiently calculate the reduced peak load when residents receives the peak price, thus guiding and executing power system demand responses.