The invention discloses an optimization model-based electric power system static state voltage stability domain boundary searching method comprising the following steps: using a ground state trend as the start point, employing the conventional optimal trend to search a first electric power system saddle-node bifurcation point and mapping same to a two dimension active injection space, and obtaining static state voltage stability domain boundary points; changing the power increase direction in the power increase direction angle reducing direction, and using the optimization model to search the electric power system saddle-node bifurcation point under the new power increase direction; if the power increase direction angle is <=0, returning to the first electric power system saddle-node bifurcation point; re-changing the power increase direction in the power increase direction angle increasing direction, re-searching the electric power system saddle-node bifurcation point under the newest power increase direction, mapping same to the two dimension active injection space, and obtaining static state voltage stability domain boundary points; if the newest power increase direction angle is >=90 degrees, connecting all static state voltage stability domain boundary points in sequence, and obtaining the static state voltage stability domain boundary.