This paper proposes an efficient method for accompanied sources’ equivalent transformation between star and delta connection. In the deduction, we adopte the comprehensive application of equivalent transformation between accompanied current and voltage sources, the transfer of unaccompanied source, and special treatment of resistances with values of 0 and ∞ Omh. The expansion of equivalent transformation analysis from the active series and parallel circuit to active star and delta connected circuit provides a convenient analysis for practical circuit.