Multi-terminal alternating current (AC)/direct current (DC) hybrid transmission technology is a promising alternative for the integration and transmission of large-scale wind power. Optimal power allocation (OPA), to distribute the active power between AC and DC transmission lines in order to minimise transmission power loss, is a significant problem to be solved. A new simplified OPA algorithm for multi-terminal AC/DC hybrid grids is proposed in this work. The power flow models of the AC grid and DC grid are separately established and linearised, and both AC and DC power losses are formulated in a simplified way. By doing so, the mathematical formula of the total power loss is expressed as a multivariate quadratic function, of which the minimum value can be directly obtained with the derivative method. Simulations based on a four-terminal AC/DC hybrid grid with wind power integration are carried out by using MATLAB, and the effectiveness of the proposed algorithm is validated by case studies.