In order to prepare lightweight constrained damping material with low density and high modulus,the surface of hollow glass microspheres was modified by A187,and the surface modification results were observed by scanning electron microscopy.Further,the modified hollow glass microspheres were added into the constrained damping coating,and the influence of the modified hollow glass microspheres on the properties of the constrained layer was investigated by the testing mechanical properties,limiting oxygen index,thermal conductivity,composite loss factor,etc.The results show that A187 can modify the surface of hollow glass microspheres.With the increase of the amount of hollow glass microspheres,the density of the constrained layer decreases,the modulus decreases,the viscosity decreases first and then increases,the oxygen index increases,and the thermal conductivity decreases.When 6%modified hollow glass micro spheres were added,the bending modulus retention rate was 90.2%,the density was reduced by 16.67%,and the overall temperature range of damping loss factor was reduced only slightly.The noise reduction characteristics of damping material were ensured while the density of constraint layer was reduced.