Rigid polyurethane foams (RPUFs) are critically challenged by their inherent high flammability and the generation of toxic smoke. In this study, we synthesized a novel, easily manufacturable hyperbranched phosphorus-containing polyol, named HPEAP. The RPUF composites containing 50 wt% HPEAP exhibited exceptional performance, notably in reducing flammability and enhancing flame retardancy. Compared to traditional RPUF and brominated RPUF, the composites with 50 wt% HPEAP showed significant reductions in peak heat release rate (65.56 %) and total heat release (72.38 %). It is noteworthy that phosphorus-based flame retardants typically have the drawback of increasing smoke production. However, the addition of 50 wt% HPEAP significantly reduced the total smoke production of RPUF by 66.34 %, overcoming a common limitation. This performance is largely attributed to the excellent thermal stability of HPEAP and its ability to promote a super high char yield. In summary, this work presents a straightforward approach for manufacturing high-performance RPUF products with enhanced fire safety characteristics, showcasing HPEAP's potential to improve the environmental and safety profiles of polyurethane foams.