The simulation of the light-guide structure of the edge-lit LED backlight source and the influence of the practical factors on the light source are studied. Firstly, the main functions and characteristics of the edge-lit backlight light structure are briefly analyzed, and the corresponding theoretical basis is provided. Then, a simplified and accurate light guide structure simulation model is proposed based on the optical characteristics of light-guide structure, and the model is simulated with the optical software of TracePro. Finally, an in-depth discussion and analysis on the characteristics and influences of light-guide structure of the LED backlight source is presented with the actual processing practice. The simulation results are verified by corresponding experiments. The influence of the essential factors on the effect of the backlight source, including the matching between the light guide structure and the LED light source, making the light guide plate thinner and designing dot scheme for high efficiency and good uniformity, is emphatically analyzed for LED backlight system. This research may offer some practical significance, for the reason that it proposes a reasonable and optimized design for light guide parameters and alleviates potential mistakes in the process of actual production.