Abstract: By using the Kahan method, a simultaneous solution for the full electromagnetic transient simulation of the AC-(LCC)DC hybrid power grids is proposed in this paper. The proposed method can achieve a high degree of spatial decoupling calculation without any iteration in the integration in each step. The simulation of the DC control systems is conducted separately from the electromagnetic transient simulation of the main HVDC equipment: The related control systems contained in the pole control layer are simulated by using analytical method; The phase-locked oscillation controller involved in the valve control layer is calculated via numerical integration by using the Kahan method. In a simple AC/DC example system, the electromagnetic transient simulation results based on the proposed method are compared with those of the PSCAD/EMTDC simulation to verify the validity and efficiency of the proposed method.