Abstract: The research of bio-fertilizer is an important step in carrying out the strategy of sustainable development of agriculture. Fermentation is the key in the process of producing bio-fertilizer. However, in current production, most factories use simple manually-operated instrument to measure pH values and temperature; thus fluctuation and unstable quality become severe problems. In order to solve these problems, SBA-P1 Fermentation Online pH-Temperature Intelligent Control System was developed by Biology Research Institute of Shandong Academy of Sciences. This system was applied to the fermentation process in Shandong Bai'ao Co. During the working process, the system draws pH value varying curves for the study of fermentation rules, controls the cycle of fermentation, and deals with abnormal fermentation timely. At the same time, auto-control of temperature could provide the bacteria with stable and suitable environment, increase the speed of growth and reproduction, and shorten the fermentation cycle. Therefore the pH-Temperature Intelligent Control System is very much suitable for the application in bio-fertilizer producing enterprises.