Multiplanar KK-type tube-gusset plate connections are the main joint types in transmission steel tubular tower, the safety of the joints are critical to the entire tower. Compared to K-joints, the mechanic characteristics of KK-joints are more complex after considering the multiplanar effects in the actual structure. Based on the bearing capacity test of K-type tube-gusset plate connections, parameterization analysis on the two kinds KK-type tube-gusset plate connections are conducted respectively, the geometric parameters and the axial force of the main tube together with other factors on the influence of the ultimate bearing capacity of multiplanar KK-joints are studied in detail. According to the results of large scale finite element parametric analysis, and considering the influence of various factors on the ultimate strength of the joints, calculation formulas of KK-type tube-gusset plate connections ultimate bearing capacity are proposed.