Process for large-scale preparation of pravastatin sodium D-type crystal

The invention relates to a process for large-scale preparation of a pravastatin sodium D-type crystal. The process comprises the following steps: 1) taking a pravastatin sodium crystal, adding an organic solvent according to the liquid-solid ratio of 0.08-0.15 mL/g at a temperature of 10-20 DEG C, and performing ultrasonic uniform mixing for 5-10 minutes to prepare mixed slurry; 2) putting the mixed slurry into a vacuum drying oven, raising the temperature to 50-70 DEG C, introducing high-purity nitrogen for 10-15 hours while performing vacuum pumping treatment, and keeping a vacuum value to be minus 0.90 - minus 0.40 MPa; 3) stopping introduction of the high-purity nitrogen, keeping the temperature at 50-70 DEG C, regulating the vacuum value to minus 0.95 - minus 1.0 MPa, drying for 10-15 hours, and obtaining the pravastatin sodium D-type crystal. The invention provides the process for the large-scale preparation of the pravastatin sodium D-type crystal, a large amount of organic solvents is not required to be used in the preparation process, and a product prepared is the white pravastatin sodium D type crystal and is high in purity.