A triangular core silicon photonic crystal fiber with double zero-dispersion points is used as the nonlinear working medium of a mid-infrared supercontinuum laser. The pumped optical fiber, with a peak power of 1500 W, pulse width of 100 fs, and wavelength range of 2.6?2.9 μm, is used to excite photonic crystal fiber with length of 0.1 m. A mid-infrared supercontinuum covering the 2?7 μm wavelength range is obtained. The spectral peak gain compensation is realized by varying the pump wavelength, and the spectral coverage of the characteristic wavelength of the detected gas is expanded. This mid-infrared supercontinuum with spectral peak gain compensation can be used to detect various greenhouse, toxic, and flammable and explosive gases in real time.