By classifying the independent nodes in the circuit，the expression of mutual conductance equal to zero can be removed. After improvement，the node voltage equation is more concise，and the computation is reduced. Based on the relation between the independent node and the generalized node，KCL equation for generalized node is modular in structure，the general expression of generalized nodal voltage equation is summarized.Analysis can prove that the voltage equation of the generalized node is not only suitable for the generalized node，which is composed of the solitary voltage source and the solitary controlled voltage source，but also can be applied to a single independent node，this voltage equation is applied more widely.