The large-scale space structures may undergo unstable Thermally Induced Vibration (TIV), called thermal-flutter, on orbit due to the special incidence angle of solar heat flux. Compared with TIV, thermal flutter can cause more serious damage to the large-scale space structures. In this paper, the primary objective of the research is to develop a method for obtaining collimating heat flux so that thermal-flutter phenomenon can be observed in the laboratory experiment. Based on the non-imaging optics theory, a parabolic reflector for infrared lamp was designed and machined. The results show that the infrared lamp array with parabolic reflector can provide collimating heat flux and the method is feasible and effective.