Carbon fiber reinforced polymer (CFRP) is widely used in space support structures for its exceptional mechanical properties, yet its weakness in the transverse direction due to resin matrix limitations remains a significant challenge [1,19]. This study investigates the effectiveness of incorporating carbon nanotube (CNT) sheets to enhance the flexural strength of thin-walled unidirectional CFRP tubes. Results demonstrate a remarkable 115% increase in flexural strength compared to tubes composed solely of unidirectional carbon fiber, highlighting the potential of CNT sheets in mitigating delamination and improving mechanical performance. However, analysis of the fiber volume fraction (FVF) reveals a lower-than expected value of approximately 40%, attributed to significant resin trapping between ii layers. This finding underscores the need for alternative manufacturing methods, such as pultrusion, to address resin entrapment and improve FVF. These findings have important implications for the design and fabrication of CFRP structures in aerospace applications. Future research efforts will focus on optimizing manufacturing techniques to enhance FVF and further improve the mechanical properties of CFRP tubes.