In order to improve the numerical calculation speed of the electromagnetic transient of power system, the s-order differential quadrature method is applied to the simulation of the electromagnetic transient, and a novel fast calculation method of the electromagnetic transient is proposed in this paper. Combined with the characteristics of V transformation, the proposed algorithm blocks the matrix with increased dimension due to the introduction of internal points, so as to avoid the direct inverse of the increased dimension matrix. With the advantage of submatrix as lower triangular structure, the inverse calculation of large-scale matrix is transformed into simple pre-generation operation and the inverse calculation of small-scale matrix, thus improving the efficiency of electromagnetic transient calculation based on differential quadrature method. Numerical examples show that the proposed algorithm can obtain the effective acceleration ratio for both linear time-varying and nonlinear power systems.