The invention belongs to the technical field of medicinal chemistry, and particularly relates to two crystal forms of azilsartan and a preparation method thereof. For the crystal form B of the azilsartan, in a X-ray powder diffraction pattern, 2theta has characteristic peaks near 7.46 degrees, 8.43 degrees, 9.38 degrees, 10.96 degrees, 18.90 degrees, 21.06 degrees, 21.98 degrees, 22.71 degrees, 23.11 degrees and 24.89 degrees. For the crystal form C, in the X-ray powder diffraction pattern, 2theta has characteristic peaks near 9.52 degrees, 11.64 degrees, 13.51 degrees, 20.85 degrees, 21.83 degrees, 22.40 degrees, 23.44 degrees, 25.17 degrees, 26.17 degrees and 29.06 degrees. The crystal form B and crystal form C of the azilsartan have better stability and fluidity and are beneficial to long-time storage.