A fast model is proposed for simulation of mask with defect based on single surface approximation in extreme-ultraviolet (EUV) lithography. In this model, the impact of defect on the reflection of the multilayer is calculated by phase perturbation and amplitude attenuation. Diffraction of the absorber is calculated by using the modified thin mask model. Taking 22 nm contact holes with pitch of 60 nm as example, compared with the waveguide method, the computation speed of the proposed model is increased more than 10 times and the critical dimension (CD) error is less than 0.6 nm. The optimal modification size for the compensation of defect is calculated by the proposed model and the result is same to that calculated by the waveguide method. Moreover, the concept of defect compensability is proposed for different defect sizes, and the defect compensability of 2D mask is discussed by using the proposed model.