Utilizing different material properties of thermal cured epoxy matrix before and after the glass transition temperature （T_g）， Kevlar29 aramid fabric/E51 epoxy resin based composites and three inflatable unfolded support booms were prepared. The fabrication process was illustrated， electrical resistant wire was used to control temperature of thermal cured matrix， and an enclosed Kapton membrane was used for inflatable pressurization to control the final shape of booms. The folding and unfolding characteristics of the support were investigated. The boom was curled and folded when T>T_g and then cooled and shaped for storage， and the unfolding process was controlled by secondary heating T>T_g and inflatable pressurization method， and the final support tube shape recovery rate was 100%. Modal analysis was used to discuss the effect of parameters such as temperature， resin content， fabric layup thickness and internal pressure of inflation on the natural frequencies of the support boom under cantilever condition. The results show that the natural frequencies of the support tube of the aramid fabric reinforced epoxy resin increase as the inflation pressure increases， the resin content increases， the fabric layup thickness increases， and the substrate temperature decreases. A curve fitting method is used to obtain the variation law of the natural frequencies with the inflation pressure and temperature， and the results can provide reference for the design of the inflatable unfolded support boom.