In this paper, we analyzed the characteristics of U-Mo/AI-Si interaction layers of dispersion fuel plates. The results show that the interaction layers （IL） are with irregular morphology and uneven thickness, and are mainly formed in the internal micro cracks of the dispersion fuel particles or at the interface between the particles and the substrates. The diffusion mechanism of U-Mo/AI-Si is the vacancy diffusion, A1 and Si are migrating elements, and the diffusion reaction is that AI and Si diffuse to U-Mo alloy. Inside the interaction layers, the AI content keeps constant basically, but the Si content gradually increases with the substrate-fuel direction, and the maximum content of Si appears interaction layers near the U-Mo side. Adding about 5wt% Si into AI matrix can restrain the diffusion reaction, and improve the performance of dispersion fuel plates finally.