With the wide application of power electronic technology, the non-sinusoidal problem of the system is increasingly prominent due to harmonic interference. On this condition, the traditional power theories are no longer applicable. Whereas, the power theory of current physical components that can correspond to different physical phenomena, which is concerned greatly. But this theory can only quantitatively analyze the active power and different reactive power components and cannot accurately describe the power characteristics in the circuit. Based on geometric algebra, a physical components power measurement method of modified current is proposed in this paper. Active power and multi-vector forms of scattered power, reactive power and generated power are established in the vector space, so that the mathematical expression and physical meaning of each power component are unified, so as to analyze the power characteristics of single-phase circuits under non-sinusoidal conditions. Each power component could directly perform related power multi-vector operations, which solves the problem of non-active power operations and followed the basic laws in the circuit. Through specific examples, the physical meaning and calculation results of each power component in the theory before and after the improvement are compared and analyzed, and the validity of the method is verified.