A method for assessing a performance-based seismic design by setting a seismic risk starts from the exceedance probability of the performance level. The method is configured to determine the structural performance level by setting an exceedance probability, determine the seismic demand when the performance level is constant, set the exceedance probability of the seismic demand in combination with the seismic risk of a set earthquake to finally determine the ground motion input and establish a novel probabilistic seismic risk assessment method that reaches the performance level. The main control and objective of the design are significantly enhanced by using this method.