In the fabrication process of holey fiber, the final geometry of the actual fiber usually deviates from the ideal. We propose a novel method based on the combination of digital image processing technique and finite element method to model the optical properties of the actual fiber rapidly. A polarization-maintaining holey fiber reported by crystal fiber A/S has been modeled and its numerical results accord with the parameters given by the data. Experimental result demonstrates that the optical properties of the fiber can be analyzed rapidly so that the draw parameters can be adjusted in time.