The invention relates to a full-color LED control device and method suitable for a passenger information system. The full-color LED control device comprises a CPU processor, and an ambient light sensor, a communication transceiver, a subtitle display processor and a color display processor which are connected to the CPU processor. The CPU processor, the subtitle display processor and the color display processor are connected with an LED driving circuit of a full-color LED display screen. The color display processor adjusts the luminous gray scale of red, green and blue colors in a color display command according to the ambient illumination intensity, then generates an optimal color display instruction and sends the optimal color display instruction to the LED driving circuit. The subtitle display processor generates a dot-matrix display instruction based on a subtitle display command and sends the dot-matrix display instruction to the LED driving circuit. The CPU processor also generates a display screen brightness adjustment command according to the ambient illumination intensity and sends the display screen brightness adjustment command to the LED driving circuit. Compared with the prior art, the full-color LED control device and method of the invention have the advantages of improving the display quality and the real-time performance and the like.