A manufacturing method of a halogen-free flame-retardant thermoplastic braided fiber reinforced polymer composite board, comprising steps of: preparing a recycled material containing a halogen-free flame-retardant thermoplastic braided fiber reinforced polymer composite; adding a polymer base material to the recycled material to form a core layer material and extruding the core layer material with a low shear extruder; hot pressing the core layer material by rollers to obtain a recycled fiber core layer; preparing a reinforcement layer containing a fiber material or a fabric with pores; and stacking and hot pressing the recycled fiber core layer and the reinforcement layer.