Disclosed in the present invention are a chalcogenide phase change material based all-optical switch and a manufacturing method therefor, relating to the field of optical communications. The all-optical switch comprises: stacked in sequence, a cover layer film, a chalcogenide phase change material film, an isolation layer film, a silicon photonic crystal, and a substrate. The silicon photonic crystal comprises a nano-porous structure such that the silicon photonic crystal has a Fano resonance effect. When the all-optical switch is used, the state of the chalcogenide phase change material film is controlled by means of laser, and the resonance state of the silicon photonic crystal is modulated to implement modulation of signal light transmissivity; the modulation range is within a communication band from 1500 nm to 1600 nm, thereby implementing an optical switch. The all-optical switch of the present invention has the characteristics of high contrast ratio, high rate and low loss.