The invention discloses a volume dissolved 
oxygen transfer coefficient staged control method based on a 
citric acid metabolic network. The metabolic flow direction is controlled through controlling the dissolved 
oxygen of 
citric acid at different 
fermentation stages, so the yield of the 
citric acid is improved. In the whole 
fermentation process of the citric acid, seed liquid is inoculated into a 
fermentation tank at the 
inoculation quantity of 8 percent, the temperature is maintained at 37 DEG C, the 
tank pressure is 0.05 MPa, the stirring speed is maintained at 84 rpm / min, and the air introduction quantity is controlled to be maintained to be 40m<3> / min in the fermentation beginning period, about 48m<3> / min in the fermentation medium period (the fermentation is started for about 2 to 3 hours) and 40m<3> / min in the fermentation later period. When the fermentation is carried out for about 58 hours, the 
reducing sugar content is detected, and the fermentation can be stopped when the 
reducing sugar content is reduced to a value lower than 5 percent. The dissolved 
oxygen transfer coefficient staged control is realized through optimizing the air introduction quantity at different fermentation stages, the improvement for improving the citric acid yield based on the 
metabolic network is realized, the process is simple and convenient and is easy to operate, the requirement on equipment is low, the 
energy consumption is little, and the method can be widely applied to citric 
acid production.