The strong vitality strains, imported with zearalenone degrading enzyme gene, were selected as initial strains, and the medium was optimized by response surface analysis. The results indicated that the optimal medium suitable for Pichia ZLHY6 was 3.5% glycerin, 0.65% yeast extract, 10% buffer solution of potassium phosphate, 1.25% ammonium sulfate, 0.45% magnesium sulfate, 0.04% calcium sulfate by optimization of multiplication medium BMGY.