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Polyurethane powder adhesives (PPAs) have a great application prospect in various areas. However, the weakly adhesion property at high temperature greatly hindered its application. In this study, nanosilica as reinforcing agent and dispersing agent has been introduced during the preparation of PPAs. A series of the polyurethane powder adhesives modified by nanosilica were prepared and the influence of adding order of nanosilica on the heat resistance and adhesive strength properties of PPAs has been investigated. The results showed that the T-peel strength of most samples after second heat (heated at 70°C for 24 hours) decreased about 60-80% comparing with the original T-peel strength. However, PPSY only decreased 17.5%, which indicated the nanosilica added after the chain extension reaction, in the prepolymer synthesis could increase the heat resistance performance of polyurethane powder adhesives. It also means the nanosilica was doped between the PU chains keeping the original form as enhancement reagent adding the nanosilica after the chain extension reaction. The excellent heat resistance performance of PPSY could meet the requirements of the industrial gluing in the fields of footwear.