In order to improve the fermentation production level of cephalosporin C, grope for appropriate inoculation amount, loading coefficient and filling water amount, variation trend of centrifugal solids and detection index of fermentation were analyzed by comparing the different inoculation quantity, loading coefficient and filling water amount. The results show that when the charge coefficient is 0.8, inoculum size is 35%, using the appropriate quantity of filling water, the fermentation index of cephalosporin C will be increased by 20%.