The formation and stability mechanism of crude oil foam is the key to solve the problem of crude oil foaming. The basic properties of foam, features of crude oil foam are introduced in this paper and the research status of crude oil foam formation and stability mechanism is expounded. The experimental research methods of crude oil foam are summarized, and the influencing factors of crude oil foam formation and stability such as the composition of oil, temperature and gas properties are discussed according to experimental methods. Based on the current research, the future direction of research is proposed. The stability mechanism of crude oil foam and the influence of mechanical action on foam are still to be studied and there is no practical test method of crude oil foam at present.