The invention relates to a method for preparing a steroidal drug intermediate. The method comprises the steps that microbial conversion is conducted on a first compound with Nocardioides simplex to obtain the steroid drug intermediate, the first compound is shown as a formula I, the steroidal drug intermediate is as shown in a formula II, and in the formula I and the formula II, R is H, a halogenatom, an alkyl group, an alkoxy group, a hydroxyl group or a phenyl group. The method selects 4, 9 (11)-pregnant-17-hydroxy group-3,20 dioxin-21-acetate as a substrate, uses only the Nocardioides simplex for biotransformation, dehydrogenation at position 1,2 and hydrolysis of acetate at position 21 are simultaneously conducted on the substrate, 1,4,9 (11)-pregnene-17,21-diol-3,20-dione is obtained, products formed through transformation are mainly the 1,4,9(11)-pregnene-17,21-diol-3,20-dione, the proportion of by-products is low, the purified products are white or off-white crystals, relativesubstrate weight yield is 75%-85%, a target product yield is high, after a HPLC analysis, the purity is >=99%, and external standard content is 98%.