The invention relates to an electric network parameter estimation method based on the parameter sensitivity of a state estimation residual error, which belongs to the technical field of electric network parameter identification of electric power systems. The electric network parameter estimation method comprises the following steps: deducing the sensitivity of the state estimation residual error for each circuit parameter of an electric network according to an actual electric network model and real-time measuring data; and modifying the circuit parameter on the prior suspicious branch circuit by adopting a linear optimization method, thereby increasing the reliability and the accuracy of application software. The electric network parameter estimation method based on the parameter sensitivity of the state estimation residual error does not have the problems of numerical stability and observation performance and has simple calculation, easy realization and high calculation speed.