Abstract: A photonic crystal waveguide optical switch based on the phase-change materials VO₂ is designed. Through plating the SU-8 cladding material onto the waveguide to compensate the temperature effect of the silicon waveguide, the temperature dependence of the waveguide switch can be reduced. An extinction ratio of approximately 9.5 dB is achieved at 1 591 nm with a thermal actuation. In addition, a new cascaded grating is designed to optimize the switch structure and achieves an extinction ratio of 27.46 dB.