Provided are a crystal form of a sesquiterpene derivative, a preparation method therefor and the use thereof. In an X-ray powder diffraction pattern of crystal form A, there are characteristic diffraction peaks at positions corresponding to the 2θ diffraction angles of 6.840±0.2, 9.390±0.2, 15.980±0.2, 16.830±0.2, 17.780±0.2, 18.760±0.2, 19.340±0.2, 20.400±0.2, 21.910±0.2, 23.280±0.2, 25.520±0.2, 26.680±0.2, 27.490±0.2, 32.110± 0.2, 32.300±0.2, 37.980±0.2 and 44.230±0.2. The crystal form A has a high degree of crystallinity and is basically non-hygroscopic; in addition, same shows more favorable dissolution kinetics and has a bioavailability that can reach 85.8%.