Aiming at the problem of low selection efficiency and low practicability of the relevant model, new algorithm is proposed for the selection of terminal guidance starting point of anti-ship missile. The idea of the algorithm is drawing the selection range of the starting point directly by analyzing the geometric position relationship among the missile, the target and the range of radar. The entire model is ran in the geodetic coordinates, and avoid using Monte Carlo method, which can brings huge calculation, so the practicability and the calculation efficiency of the algorithm was improved. The simulation results verified the validity of the model.