The plugging performance of the foam is strongly affected by the environment pressure. The back pressure is set to 10 MPa to simulate the environment pressure of the foam, in order to study the influencing factors of the plugging performance of the foam under the reservoir pressure. The nitrogen is chosen as the gas phase medium. The influencing factors studied in this paper include the reservoir pressure, the gas liquid ratio, the permeability, the oil saturation and the dip angle. It is shown that the plugging performance of the nitrogen foam is affected by the reservoir pressure. The greater the reservoir pressure is, the smaller the resistance effect will be. Within a certain range, the higher the gas liquid ratio of foam is, the better the plugging performance will be. The pore structure of the reservoir affects the generation of the foam, so that the higher the permeability is, the higher the plugging ability of the foam will be. Under the condition of a low oil saturation, the foam still has a certain plugging effect. But because the plugging period of a valid foam is very short, the nitrogen foam can only have a temporary plugging effect in the low oil saturation reservoir. The nitrogen foam is better distributed in the angle reservoir, where the plugging resistance of the nitrogen foam is higher. In the meantime, it is indicated that the plugging performance of the foam is better in the vertical direction.