The light source of traditional edge-lit backlight modules typically consists of LED bars which composed of multiple LED chips. However, the spacing between the chips can create distinct bright and dark spots (Hot Spot) on the input surface of the light guide plate (LGP), thereby affecting the optical performance of the backlight module. In this paper, we proposed an edge-lit backlight module with staggered light bars, incorporating a light propagation cavity design to enhance light receiving efficiency and eliminate Hot Spot. Firstly, we designed the structure of the staggered light bars and the light propagation cavity. Secondly, the advantages of the new backlight module design in eliminating Hot Spot were verified through TracePro simulations. The simulation results showed that the maximum irradiance of the backlight module reached 81,010 W/m2, and the luminance uniformity peaked at 75.142 %. Compared to the traditional backlight modules, the light receiving efficiency was increased by 6.62 %, and the luminance uniformity was improved by 1.34 times, which effectively mitigated the Hot Spot. Finally, we discussed the impact of the improved backlight module in reducing the thickness of the LGP and decreasing the number of LED chips, achieved superior optical performance. This study demonstrates the significant advantages of the light propagation cavity in eliminating Hot Spot within backlight modules.