The invention relates to a low-voltage user junction box for a power distribution network. The device comprises a box body, and the interior of the box body is provided with a knife switch, an air switch or electric leakage protection device and a three-phase four-wire copper busbar which are sequentially connected through cables. The cables comprise an outgoing cable and an incoming cable. A partition plate is arranged on the box body, and a U-shaped groove is formed in the partition plate. The outgoing cable is arranged in a rectangular groove, and a T-shaped pressing plate with a T-shaped longitudinal section is arranged in the U-shaped groove. The T-shaped pressing plate comprises a transverse pressing part and a longitudinal pressing part, wherein the longitudinal pressing part is inserted into the U-shaped groove, the transverse pressing part is pressed on the partition plate, and the transverse pressing part is fixed on the partition plate through a bolt. A cable inlet hole anda cable outlet hole for penetrating cables are formed at the bottom of the box body. According to the branching method, the outgoing cable is fixed to the partition plate; when the position needs to be changed, the bolt on the transverse pressing part is unscrewed, the T-shaped pressing plate is taken out of the U-shaped groove, and the position of the outgoing cable is changed. The junction box is simple to use, qualified in quality, low in cost and convenient to maintain.