The halogenation reactor skid for brominated butyl rubber employs a horizontal pipe mixer structure, featuring two inlets, one outlet, and multiple sensor interfaces. Inside, it is equipped with a flow guide tube and specially-shaped baffles, combined with an efficient axial-flow agitator to achieve effective online mixing and reaction. Additionally, it is equipped with a PLAN53A+32 sealing auxiliary system to ensure tight sealing. This skid-mounted online mixer is suitable for various process scenarios requiring online mixing, allowing adjustment of the average circulation times based on requirements. Moreover, it can be optionally equipped with the Great Wall patented coaxial centrifugal pump outlet module, tailored to the head requirements of the pipeline.