We theoretically and numerically investigate all-optical Mach–Zehnder interferometer switching based on the phase-shift multiplication effect of an all-optical analog on the electromagnetically induced transparency effect. The free-carrier plasma dispersion effect modulation method is applied to improve the tuning rate with a response time of picoseconds. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Compared with no phase-shift multiplication effect, the average pump power of all-optical switching required to yield the -phase shift difference decreases by 55.1%, and the size of the modulation region is reduced by 50.1% when the average pump power reaches 60.8 mW. This work provides a new direction for low-power consumption and miniaturization of microstructure integration light-controlled switching devices in optical communication and quantum information processing.