The invention discloses a letter box device. The device comprises a box body, an installation shell which is fixedly mounted in the box body, and an LED illuminating lamp which heads into the installation shell; a plurality of clapboards are fixedly mounted in the box body in an up-down parallel mode, a letter box is arranged between every two adjacent clapboards, a first empty warehouse and a second empty warehouse which is located on the right side of the first empty warehouse and is communicated with the first empty warehouse are formed in the installation shell, a jack socket which is communicated with the second empty warehouse is formed in the right side end face of the installation shell, and a sliding board which can horizontally translate left and right is arranged in the first empty warehouse; the letter box device is simple in overall structure, low in manufacturing cost, safe and reliable in power supply and simple and convenient in assembly and disassembly operations, reduces electric shock accidents effectively, guarantees the life safety of people, ensures the normal usage of the LED illuminating lamp and is suitable for popularization and generalization.