Koji making method for increasing protease content

The invention provides a starter propagation method for increasing the protease content, and belongs to the technical field of condiment manufacturing. The starter propagation method for increasing the protease content comprises the following steps: preparing a protein soybean raw material and a starchy wheat raw material, inoculating aspergillus oryzae, mixing and stirring, and performing starter propagation; the starter propagation is divided into a first culture stage, a second culture stage, a third culture stage and a fourth culture stage according to starter propagation time; the first culture stage is 0-13 hours for starter propagation; in the second culture stage, the starter propagation time is 14-21 hours; in the third culture stage, the starter propagation time is 22-30 hours; the fourth culture stage is 31-44 hours of starter propagation. According to the method, oxygen requirements in different growth stages of aspergillus oryzae are designed, and the metabolic heat production rule of aspergillus