By in-door model experiment of double-layer soil foundation, the bearing capacity of doublelayer foundation was studied with upper hard pans of variable thickness and strength, and the digital photograph of deformation field of the double -layer foundation was taken for analysis. The analysis of p -s curve of pressuring-loading and sedimentation indicates the limit enduring capacity of double-layer foundation increase with the increase of upper hard pan thickness and strength, while the corresponding vertical displacement decrease as the upper hard pan thickness and strength increasing under limit enduring condition. The upper pan with water-cement ratio and thickness respectively as 10% and 30 mm shows different capacity performances with that of water-cement ratio and thickness respectively as 20% and 60mm, with the limit enduring capacity of latter is 3.01 times that of former, and the corresponding sedimentation is 0.11 times that of former under limit enduring foundation. By the technique of DPDM (digital photogrammetry for deformation measurement) the digital photographic analysis of double -layer foundation deformation field was conducted, the results of grid-diagram analysis shows the initial deformation occurred to the lower soft clay, and the deformation zone in grid-diagram stretched gradually upwards to hard pan, downwards to soft clay and stretch horizontally with the increase of loading. The breakdown mode of double-layer foundation is the comprehensive breakdown mode featured by cone-shaped block shear of upper hard pan and punching shear of lower soft clay. The optimization and designing of upper hard pan strength and thickness is of significance in improving foundation reinforcement.