The invention provides a levamlodipine besylate crystal with the molecular formula being (C20H25ClN2O5) (C6H6O3S) (H2O) 1.5 and the molecular weight being 594.07. Crystallography measurement parameters are a monoclinic system and P21 chirality space groups, and the chirality absolute configuration is determined by crystallography Flack parameter being 0.08(6); the unit cell size is shown in the specification, wherein beta is 95.817(4) degrees, and V is 2880.1(11). The characteristic peak in an X-ray powder diffraction pattern (Cu-Kalpha) is displayed at 2thea being 6.70 degrees, 10.12 degrees, 12.40 degrees, 13.36 degrees, 13.68 degrees, 17.04 degrees, 22.46 degrees and 24.16 degrees. The invention further provides a preparation method and application of the levamlodipine besylate crystal. The levamlodipine besylate crystal has the specific crystal form and the amount of crystal water and specific crystallography main parameters and the exact atom spatial position, the solubleness and stability of existing levamlodipine besylate are improved, the stability and bioavailability of the levamlodipine besylate tablet can be improved, preparation is easy, the cost is low, and the obtained crystal is regular in form, uniform in particle size and suitable for large-scale application and popularization.