Image inpainting technique aims at infilling the images with missing or damaged portions in a way that they will be non-detectable for an observer.The Criminisi algorithm in the image inpainting is introduced. An improved algorithm is proposed to tackle the existing problem. These new improvements are in four aspects.Firstly, a new priority function is used to adjust the order of the selected pixel block, and therefore the incorrect filling order caused by rapid decay of data term is avoided. Secondly, a Sobel operator is introduced to improve computing method of isophote intensity,making the inpainting order along the isophotes. Thirdly, a new matching searching method to identify the samples in the neighborhood of the damaged region based on similarity is employed. Finally, to smooth the propagation of error in updating the confidence value, a new formula is defined. Experimental results show the improved algorithm can get a satisfied inpainting result and improve repairing efficiency.