Abstract: In this study, to overcome the shortcomings of the present models, based on the analysis of the force balance of the bubble, considering the contact angle and capillary wicking effects, a Al₂O₃ nanofluid critical heat flux（CHF） mechanism model is developed. It is shown that, this model can simulate the effect of nanofluid concentration(c_NF) on CHF, that is, as c_NF increases, CHF increases at the beginning, and when NFc is greater than a certain value, CHF no longer increases and maintains a constant value, and this model can explain that the diameter of nanoparticle（d₀） has no effect on CHF, which are in a good agreement with experimental results. As the contact angle or inclination angle increases, calculated CHF by this model decreases.