The invention relates to an infrared-permeable calcium aluminate glass preparation method. The method includes: a, well mixing calcium source power and aluminum source powder in a mole ratio of Ca to Al being 0.85:1-3:1; b, prepressing for blocking the mixture powder, and sintering under the condition of air or atmosphere; c, subjecting sintered blocks to founding in an air suspension furnace to obtain aluminate glass; d, subjecting the prepared aluminate glass to thermal treatment. The calcium aluminate glass prepared by the method has excellent transmittance in visible regions, near infrared regions and intermediate infrared regions and is expected to be an important infrared window material, a fluorescence substrate material and a laser medium material.