Abstract: An OPC modeling method is disclosed, which includes: step S1: determining optical model parameters and resist model parameters; step S2: obtaining a plurality of parameter combinations by stochastically choosing values for the parameters; step S3: performing photolithography simulations and etching wafers and calculating RMS values of differences between simulated CDs and etching CDs and BCE values of the CDs; step S4: evaluating the values according to Pareto principle and calculating Pareto optimum to N-th-best Pareto suboptimum sets to prioritize the plurality of parameter combinations in a descending order; step S5: applying a genetic algorithm with position-based crossover and/or mutation to the plurality of parameter combinations, to obtain new parameter combinations; and step S6: iterating steps S3 to S5 on the new parameter combinations until a number of iterations reaches a first predetermined value and using highest prioritized ones of parameter combinations resulting from a last iteration for OPC m