The construction of irregular steel pipe tree shaped column nodes is complex, and the use of cover plates to connect the trunk and branches can greatly reduce the difficulty of construction. Understanding the influence of cover plate stiffeners on the mechanical properties of such nodes is of great significance for guiding the design of similar projects. This article takes the special-shaped steel pipe tree column at Chongqing East Station as an example, and conducts scaled tests on two nodes with or without stiffeners to study the influence of stiffeners on key indicators such as force transmission mechanism, stress distribution and level, node failure mode, and node bearing capacity in the node area of the special-shaped steel pipe tree column. The research results indicate that the stiffness of the cover plate is greatly improved after the installation of stiffeners; After setting the stiffeners, the stress distribution in the node area, especially in the cover plate, tends to flatten and the peak stress decreases; Similar to nodes without stiffeners, in the later stage of loading, nodes with stiffeners experienced strength and local instability failure at the roots of the branches. However, with stiffeners, the degree of local bulging of the cover plate and node area trunk was significantly reduced; The bearing capacity of the node is significantly improved after the installation of stiffeners.