Longdong Jurassic reservoir is a typical severe heterogeneous reservoir. Water flooding in this area is ineffective owing to water breakthrough and water flush. Laboratory experiments and field application of air foam flooding are described in this paper. Firstly, the air foam agent formula that suitable for Longdong Jurassic reservoir is selected as 0.5wt%HD-6 + 0.15wt%HD-Y by studying the foaming ability, stability and interfacial tension between oil and surfactant solution. The oil displacement results indicate that air foam flooding is more effective than the usage of surfactant waterflooding and air injection considering the amount of acquired recovery factor. In addition, process parameters of air foam flooding are determined by core flooding tests. The gas/liquid ratio is set to 3:1 and the chemical slug size is set to 0.9PV. Based on the experiments, air foam flooding is applied in Maling Block, the performance indicates that this technique can increase injection pressure, improve the injection profile of reservoir, decrease the water cut and improve the oil production.