The development of most oilfields in China is challenged by such problems as low recovery factor，serious wax formation in wellbore and pipelines，and insufficient gel breaking during stimulation for low-temperature reservoirs. Microbes are widely used in oilfield development due to the properties of their metabolic products. This paper makes an overview of the research of microbial technology and its application in oilfields in respect of enhanced oil recovery （EOR），wax removal and control，and fracturing fluid gel breaking. The paper explains the mechanism of microbial technology in three areas，summarizes the advantages and disadvantages of the application of microbial technology in oilfields，and makes an outlook for the research focus of microbial technology in future oilfield development.