The invention discloses a dummy pattern filling method. The method comprises the following steps of 1, determining a dummy pattern filling rule according to a required value of a data ratio of a pattern and a pattern isolation rule; 2, finding out a blank region required to be subjected to dummy pattern filling in a layout; and 3, performing dummy pattern filling in the blank region of the layout according to the dummy pattern filling rule. According to the method, intelligent dummy pattern filling can be realized, so that the data ratio of the pattern subjected to the dummy pattern filing is infinitely approximate to the required value.