In process of exploring the complex fault-block reservoir with edge water， water coning problem will be more and more serious， which will lead to excessive water production and reduce the oil production. A related experimental model was developed to evaluate the effectiveness of nitrogen foam preventing edge water coning in huff-n-puff wells by comparing with that of single nitrogen system and surfactant-polymer system. The model also was used to analyze the effect factor， optimize injection parameters of nitrogen foam and study on its mechanism. The results showed that the nitrogen foam was not only combined with both advantages of nitrogen and surfactant-polymer， but also had its own superiority in preventing edge water coning in puff and huff wells， the huff-n-puff wells’oil displacement efficiency increased by 6.12%， and the water cut decreased by 21.81% after nitrogen foam stimulating. Moreover，the ability of nitrogen foam to inhibition edge water coning would gain an ideal result with heterogeneous reservoir and low viscosity oil. When the edge water was insufficient， conversed in pump’ s velocity 0.5 mL/min， the application of nitrogen foam would be more successful in controlling edge water coning as edge water force weakening. When the edge water is more adequate， conversed in pump’ s velocity 2.5 mL/min， with the volume of injecting foam selected 0.1 PV and the option of soaking time chosen 24 h， the stimulation of nitrogen foam in huff-n-puff wells would be more effective in preventing edge water and achieve more profit margin.