The invention discloses a letter box device convenient to maintain. The letter box device comprises a box body, wherein strip-shaped partition plates are mounted in parallel up and down inside the box body; a letter box is arranged between every two partition plates; a mounting shell and a lighting lamp are arranged at the top of the box body; a left sliding cavity is formed inside the mounting shell; a right sliding cavity is further formed in the right side of the left sliding cavity inside the mounting shell; an inserting hole which is communicated with the right sliding cavity is formed in the right end surface of the mounting shell; a power supply cavity opposite to the inserting hole is formed in the left end part of the right sliding cavity; and a first sliding moving block which can move leftwards and rightwards is arranged in the right sliding cavity. The letter box device is relatively simple in overall structure, circuit connection operation between a mounting box and the power supply cavity is automatically completed through a first motor, the mounting shell and the lighting lamp are simply electrified and connected in an insertion manner, in addition, electric shock is avoided in the electrification and insertion process, and the letter box device is simple to operate and applicable to popularization and application.