Computational efficiency is an important aspect of power flow algorithms. A new combination algorithm based on higher-order Newton and simplified Newton method is proposed. Firstly, the solution principles of the high-order Newton method and the classical Newton method are compared and analyzed; Furthermore, the high-order Newton method and the simplified Newton method are combined, and the detailed solving steps of the combination algorithm are given. Through the reasonable collocation of the high and low order Newton method, the calculation time is reduced and the efficiency of power flow calculation is effectively improved. At last, based on the IEEE AC system examples, the validity and correctness of the proposed method for solving power flow calculation are verified by comparing the results of basic case test, algorithm efficiency and system heavy load, etc.