Abstract: A series of TMI-type macromolecular dispersion stabilizers with unsaturated double bonds at the end of the chain were synthesized from polyether polyol and 3-isopropyl-dimethylbenzyl isocyanate (TMI) under suitable temperature and catalyst conditions. The homemade TMI-type macromolecular dispersion stabilizers were involved in the synthesis of polymer polyol (POP) by dispersion polymerization, during which a series of POPs with different viscosity and solid content were formed by co-polymerization with styrene and acrylonitrile. The effect of the reaction conditions on the viscosity and solid content of the POPs was investigated by varying the capping ratio（n（—NCO）∶n（—OH））, the mass fraction of the macromolecular dispersion stabilizer in the base synthesis formulation, and the molecular weight of the polyether used as a solvent. When the capping ratio of TMI-type macromolecular dispersion stabilizer was between 0.8∶6 and 1∶6, the mass fraction of macromolecular dispersion stabilizer in the basic synthesis formula was 4%, and the lower molecular weight polyether was used as the solvent in the basic synthesis formula, POPs with solid content higher than 40% and viscosity lower than 4 500 mPa·s could be synthesized.