A dummy pattern filling method, including: Step I, determining the rule of filling dummy patterns, in accordance with required DR values and isolation rules of patterns; Step II, finding out blank Fields within said layout that need to be filled with dummy patterns; Step III, by following said rule of filling dummy patterns, filling dummy patterns within blank Fields on layouts. Implementing a Smart Dummy Pattern Filling, which enables the Data Ratio (DR) of dummy patterns to come infinitely close the required DR value after completing the filling of dummy patterns.