The general approaches of circuit analysis are node voltage analysis and loop current analysis. Also， loop and node are concepts of graph theory. According to circuit analysis and graph theory，a new way called cut-set voltage analysis has been proposed and verified. In addition， the rules of cut-set voltage equations have been raised based on the rules of node voltage equations and loop current equations. The new approach not only avoids complex matrix operation and establishes the equations directly，but also contributes effectively to analyze circuit network from the angle of graph theory.