The invention provides an anti-falling cable branch box. The anti-falling cable branch box comprises a branch box body, first fixing holes, an air collecting cover, air inlet holes, limiting grooves,a movable cover, air storage cavities, air inlet pipes, tapping sleeve heads, first shunting pipes, second shunting pipes, air inducing grooves, limiting chucks, reinforcing rods, counterweight chassises, second fixing holes, bolt holes, extruding plates, extruding blocks and counterweight blocks. The first fixing holes penetrate the two sides of the upper middle portion of the branch box body. When the extruding plates are pressed against the counterweight blocks, the inverted splayed extruding blocks exert a vertical tension on the counterweight blocks. The contact area between the extrudingblocks and the counterweight blocks can be increased when the extruding blocks are opened up and down. The stability of the four sides of the counterweight blocks is further enhanced. The overall tilting prevention performance of the branch box body, the counterweight chassises and the counterweight blocks which are connected by means of the reinforcing rods can be improved. With the cooperationof an original cement pier, a set of tilting prevention structures are additionally arranged at the bottom of the branch box body. Therefore, the usage efficiency of the coastal area branch box is improved.