In the steroid biocatalytic process, adding hydrophilic organic solvent to the fermentation medium is an effective method to increase the substrate solubility and the conversion efficiency, but organic solvents are often toxic to mycelium. To solve this problem, the Penicillium raistrickii p-10-8 was mutated by N+ ion implantation, and an organic solvent tolerant strain named 60 A-5-8 was obtained, of which the conversion rate reached 82.61% when the amount of substrate increase 4‰. In addition, the mutant strain shows high genetic stability even after 5 generations of cultivation.Cited