The present invention relates to the field of electric system security constrained economic dispatching, and provides a security constrained economic dispatching method for embedded reactive power and voltage. The method comprises: first constructing an optimal power flow model of security constrained economic dispatching composed of an objective function and a constraint condition; after the model is iteratively solved, checking a per unit error for all branch lines; if a line exists which does not meet the per unit error, updating a power flow equation constraint, and performing next iteration until all the lines meet the per unit error; converging the model, and ending the iteration ends to obtain a whole set of electric system security constrained economic dispatching scheme containing node voltage amplitude, a voltage phase angle, unit active power output and reactive power output. The present invention can maximally meet electric system economic operation requirements and reduce electric system operation cost, is high in precision and good in convergence, and has high practical application value.