The invention relates to two methods for preparing sterile powder of cefoselis sulfate. The method in one embodiment comprises the following steps: dissolving the raw material of cefoselis sulfate with an appropriate amount of dimethyl sulfoxide in a sterile room, eliminating the heat source, adding an appropriate amount of poor solvent, performing recrystallization and obtaining sterile powder of cefoselis sulfate. The method in another embodiment comprises the following steps: adding the raw material of cefoselis sulfate into an appropriate amount of water in a sterile room, adding alkalinereagent, eliminating the heat source after the solid is dissolved, adding sulfuric acid, performing recrystallization and obtaining sterile powder of cefoselis sulfate.The methods for preparing sterile powder of cefoselis sulfate have the advantages that the recrystallization is easy, the time for recrystallization is short, and purification can be performed to unqualified sterile powder of cefoselis sulfate again, so as to reduce the loss.