The number of nodes in ultra dense visible light communication networks is huge, and the connection relationships between nodes are complex. Key communication nodes carry a large amount of data streams and communication tasks, which can provide important reference for resource allocation. Therefore, a resource allocation method for ultra dense visible light communication networks based on improved differential evolution method is proposed. Calculate the information carrying capacity of ultra dense visible light communication links based on channel gain, signal-to-noise ratio, and communication interruption probability. Determine key communication nodes based on node blocking probability. Build a resource allocation model based on link information carrying capacity and key communication nodes. Use an improved differential evolution algorithm to solve the model and achieve optimal resource allocation for ultra dense visible light communication networks. The experimental results show that the proposed method can effectively improve the data transmission rate and throughput of ultra dense visible light communication networks, and has good practical application effects.