The invention provides a spectrum widening device based on a large-mode field anti-resonance hollow-core photonic crystal fiber. The spectrum widening device comprises a fiber chirped Yb amplifier, a telescope, a plano-convex lens, a first vacuum cavity window sheet, a first vacuum cavity, an anti-resonance hollow-core photonic crystal fiber, a second vacuum cavity, a second vacuum cavity window sheet, a first vacuum barometer, a second vacuum barometer, a first gas path valve, a vacuum pump, a second gas path valve, a third gas path valve, a fourth gas path valve, a vacuum gas tube, a pressure detection valve, a high pressure gas bottle, inert gas and a spectrometer. The invention also provides a use method of the spectrum widening device. The is advantaged by simple structure, flexible operation and highly-efficient transmission, and has a quite wide application prospect in the field of the generation of super continuous spectrums, the pulse shaping technology, the generation of attosecond pulse and the fiber communication.