To restore the underexposure image, an illumination compensation inpainting model which employs the joint-diffused partial differential equations (PDEs) is proposed. Firstly, the novel model compensates the illumination effect in multi-scaled underexposure images respectively. Secondly, the information in the fused compensated image is restored by PDEs which diffuse the geometric property and gray information into the target region simultaneously. Experimental results demonstrate that the novel model can properly restore scratches while compensating the illumination effect in underexposure image, and the joint-diffused PDEs which are employed in it lead to a better performance than the conventional PDE inpainting models.