The invention discloses a novel letter box device. The novel letter box device comprises a letter box body, an installation body sleeve and an energy-saving lamp used for being matched to be connected with the installation body shell. A plurality of sets of partition plates are transversely distributed in the letter box body at equal intervals. Letter boxes are installed between every set of the partition plates. A lock bar is arranged at the center of the right end face of the energy-saving lamp. A first touch block is arranged at the center of the right end face of the lock bar. A lock groove which is through up and down is formed in the lock bar. A cavity is formed in the left end face of the installation body sleeve. A first electricity inlet is formed in the center of the right end wall of the cavity. Two sliding body grooves with the left end communicating with the cavity are oppositely formed in the installation body sleeve front and back. Two sliding bodies are oppositely arranged in the two sliding body grooves. The novel letter box device is simple in structure, safe, reliable, and easy and convenient to operate. The mounting and dismounting efficiency of the energy-saving lamp is high, electric shock accidents caused in the mounting and dismounting process of the energy-saving lamp are effectively avoided, and the service life of the energy-saving lamp and the letter boxes is prolonged.