The present invention relates to a method for adjusting the strength of turn-based game automatically. The method provides a search algorithm for inquiry and giving decision results. The decision results can be used for filtering and giving filtered results. Then a probability distribution result can be provided to control the virtual node inside the computer host. Furthermore, the game result can be used for adjusting the performance of the virtual node in the game. Thereby, the client node can evaluate its performance in the game conveniently.