Abstract: In order to consider the spatial effect and influence of joints，three-dimensional space models were created by using ABAQUS program． The bearing capacity，stress distribution and deformation of connection plates thickness were analyzed for the K-type and KT-type tubular truss joints，and the mechanical performances after reducing connection plate thickness was examined． It was clearly that the joints had no obvious phenomena under design load， the members and connection plates were in the elastic state． The parts of connection plate were in plastic state after the thicknesses of the connection plates was reduced，but the yield region was smaller and not connected，the overall stability of the tubular joint was good． Which show that the optimized thickness of the connection plate can meet the requirements of engineering design，which is safe and economic．