The invention relates to Crystal form I and Crystal form II of dihydrochloride 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 therefor, wherein the Crystal form I has an X-ray powder diffraction pattern having characteristic peaks at the 2 ¸ positions of 6.0±0.2°, 7.3±0.2°, 11.7±0.2°, 12.9±0.2°, 18.4±0.2°, 24.7±0.2°, and 26.3±0.2°, as determined by using Cu-K± radiation, and the Crystal form II has an X-ray powder diffraction pattern having characteristic peaks at the 2 ¸ positions of 5.0±0.2°, 7.0±0.2°, 10.1±0.2°, 17.0±0.2°, 26.0±0.2°, and 26.5±0.2°, as determined by using Cu-K± radiation.
