The honeycomb structure can be applied to the design of new lightweight composites materials due to its excellent properties such as high strength,strong energy absorption ability, low thermal conductivity, etc. In recent years, researchers have noticed that cell joint performance optimization can improve the performance of honeycomb structures. In this study, an optimized honeycomb structure with cell joint thickened was obtained by a theoretical analysis in which two principal geometrical parameters were adjusted, and then fabricated with additive manufacturing technology for compression testing. The results were obtained through experimentation and qualitative simulation, and then compared with those of a traditional honeycomb structure with uniform wall thickness. Finally, the mechanism of the optimized thickened-joint honeycomb structure was investigated, which could be a design guideline for the application of honeycomb structures in various engineering fields.