Abstract: The spatial resolution is one of the key performance parameters of an industry computed tomography(ICT) device. A virtual-focal-spot-based method for high-resolution image reconstruction was proposed. The actual focal spot of X-ray tube into two virtual focal spots was decomposed so that the accumulation of the weighted distributions of the virtual focal spots was approximate to the distribution of the actual focal spot of X-ray tube. Thus, a datum detected by a detector cell could be thought of as the combined contribution from two virtual focal spots. Then high-resolution image by using the improved interpolative algebraic reconstruction technique(IIART) was reconstructed. The validity of the proposed method is verified by numerical experiments.