The invention provides an N-1 closed-loop safety checking method with embedded reactive power and voltage, and belongs to the field of electric power system safety constraint economic dispatching. According to the method, first an optimal power flow model of embedded reactive power and voltage is built and solved, and if the model converges, a current optimal solution of the model is output and N-1 checking is performed; each line is disconnected in sequence, sets with constraint being out of limit are calculated; if out-of-limit sets do not exist, the current optimal solution of the model isoutput; if the out-of-limit sets exist, a sensitivity matrix is calculated for open-circuit lines where an out-of-limit situation exists and a corresponding N-1 out-of-limit scene constraint is generated to be added to a constraint condition of the model, iteration of a next time is performed till lines in each of the current calculated out-of-limit sets after iteration are not increased comparedwith lines in out-of-limit sets corresponding to iteration of the last time, and the current optimal solution of the model is output. The N-1 closed-loop safety checking method with embedded reactivepower and voltage satisfies the actual operation condition of an electric power system, and has very high practical application value.