The　weighting　factors　method　and　the　response　surface　methodology　are　used　to　achieve　multi-objective　optimization　of　a　dielectric　layer　photonic　crystal　filter.　The　size　of　period　and　the　transmission　quantity　are　considered　simultaneously　and　a　multi-objective　optimization　model　of　filter　is　established,　which　takes　the　size　of　period　and　transmission　quantity　to　be　minimized　in　stop-band　as　objectives.　Global　approximate　expressions　of　the　objective　and　the　constraint　functions　are　found　by　response　surface　methodology.　Then　the　weighting　factors　method　is　employed　to　convert　the　model　into　a　quadratic　programming　model　and　the　optimal　parameters　can　be　obtained　using　sequence　quadratic　programming.　Examples　provide　the　optimized　results　in　three　different　weight　coefficients.　The　effect　of　the　weighting　factors　on　the　value　of　the　objective　function　is　also　discussed.　Results　show　that　the　present　method　is　precise　and　efficient　for　multi-objective　optimization　of　a　dielectric　layer　photonic　crystal　filter.