Aiming at the problems of uneven illumination,low contrast and unclea r texture details of magnetic tile surface defect image,an improved homomorphic filtering and the successive mean quantization transform (SMQT) algorithm is proposed to enhance the surface defect image of magnetic tile.Firstly,the improved Butterworth transfer function is used to replace the transfer function in the traditional homomorphic filter to decompose the image into high -frequency image and low-frequency image;secondly,the SMQT algorithm is used to nonlinear stre tch the gray range of the high-frequency image to extend it to the whole gray-scale region, so as to achieve the purpose of enhancing the high-frequency image;finally,the low-frequency imag e and the processed high-frequency image are fused to get the enhanced image.The experim ental results show that the proposed algorithm can effectively improve the uneven illumination of the magnetic tile surface defect image,improve the contrast of the image,enhance the textur e details of the image,and make the defect part and detail part of the image more visible.