Microemulsion and foam floodings are two important technics in enhanced oil recovery (EOR). The former one enhances the microscopic oil recovery efficiency, i.e., displacement efficiency, by using surfactant to increase solubilization ratio and decrease oil-water interfacial tension and capillary pressure; the latter one enhances the macroscopic oil recovery efficiency, i.e., sweep efficiency, by using foaming agent to generate foam in reservoir pores for blocking preferential flowing channels and swept zones. The advantages and limitations of two technics are illustrated here through the review of their developments and research advances. Microemulsion-foam flooding, also known as low-tension-foam flooding, that is a novel EOR technic proposed recently, can combine the advantages of the individual method, meanwhile overcome their limitations, ultimately enhance both microscopic and macroscopic oil recovery efficiency. However, there are theoretical and practical challenges for the microemulsion-foam EOR. By reviewing the research advances of this EOR method, the current challenges, potential solutions and research suggestions are discussed in details.