Beam-guiding system (BGS) in the target area of a laser-driver maps the rectangular arrangement at the main lasers to a spherical geometry configuration of shooting lasers at the target chamber. It also ensures that all the laser beams share the same light path length when they arrive at the target chamber center. With the output energy raising from 2MJ to 5MJ@3ω, the laser beam quantity will increase to more than 500. In this situation, researches were conducted on the relationship among the beam quantity, beam combination fashion in the target area and the radius of the target chamber. Also, beam transmission units (BTU), including transmission models of main lasers and shooting lasers and the switch manner between them, was put forward to simply the BGS arrangement work. Then we discussed the factors that determine the BTU configuration and general target area shape. Based on the beam combination fashion and BTU, the entire BGS arrangement in the target area of a 5.76MJ@3ω indirect-drive laser facility with 576 laser beams was figured out.