The invention relates to Crystal form I, Crystal form II and Crystal form III of N-(4-((3-chloro-4-fluorophenyl)amino)-7-((7-methyl-7-azaspiro[3.5]nonan-2-yl)methoxy)quinazoli n-6-yl)acrylamide represented by the following Formula (I), and preparation methods thereof, wherein the Crystal form I has an X-ray powder diffraction pattern having characteristic peaks at the 2θ positions of 6.7±0.2°, 7.9±0.2°, 8.6±0.2°, 12.0±0.2°, 13.9±0.2°, 15.9±0.2°, 17.3±0.2°, 18.3±0.2°, 18.7±0.2°, 21.0±0.2°, and 23.0±0.2°, as determined by using Cu-Ka radiation； the Crystal form II has an X-ray powder diffraction pattern having characteristic peaks at the 2θ positions of 6.9±0.2°, 8.5±0.2°, 14.8±0.2°, 15.6±0.2°, 16.7±0.2°, 17.1±0.2°, 17.9±0.2°, 18.7±0.2°, 19.1±0.2°, 21.5±0.2°, 23.5±0.2°, and 25.7±0.2°, as determined by using Cu-Ka radiation； and the Crystal form III has an X-ray powder diffraction pattern having characteristic peaks at the 2θ positions of 4.9±0.2°, 6.1±0.2°, 7.4±0.2°, 11.4±0.2°, 12.2±0.2°, 16.6±0.2°, and 18.4±0.2°, as determined by using Cu-Ka radiation.
