Abstract: This paper proposes an all-dielectric optical switch model based on phase-change material Ge-Sb-Te (GST) in the 1550nm band.The optical switch model combining metal and phase-change material is studied to achieve the modulation of incident waves.The internal mechanism of resonance generated by the optical switch is simulated and analyzed.The effects of the size and material of the resonator on the resonant response of the optical switch are discussed.The optical switch effect of phasechange material Ge-Sb-Te (GST) is compared.The modulation depth, sensitivity and quality factor are introduced to evaluate the performance of the optical switch.The study finds that aluminum has the sensitivity, which can reach 0.834 when the radius is 170nm.Copper and gold have the best modulation depth, which are 28.22% and 57.09% respectively.At the same time, considering the production cost, aluminum or copper should be selected as the material of the all-dielectric optical switch according to the actual needs.Theintroduction of phase-change materials greatly improves the flexibility of the optical switch and provides new ideas for the design of the optical switch.