This paper investigated the heat transfer of high temperature jet impinging a cross-shaped plate. An experimental mockup was designed and used to produce high temperature (similar to 500 degrees C) impinging gas jet with stable high speed (similar to 56 m/s) at the nozzle exit. A one-dimensional theoretical model was proposed to predict the temperature increment of the back-side surface(s) that opposed to the impinging surface, by simplifying and assuming the heat transfer process can be governed by convection. Three materials were selected due to its potential high heat transfer resistance, speedy installation and long duration under severe impinging conditions. For each material, four types of thermal insulation structures were designed and subjected for testing. The following conclusions from comparison of the results of the model predictions with experimental data can be drawn. The proposed simplified one-dimensional model can be used to predict heat transfer at the back-side under high temperature and high-speed impinging. The optimal case among the 12 thermal protecting designs was obtained, majorly due to low back temperature and less material consumption.