Based on the analysis of the reason that the TSS algorithm is unfit for searching low drastic video sequence，an extensible three step search algorithm（TSS）is proposed based on the prediction of initial point and enhanced searching in small range .The proposed algorithm has a significant improvement over the TSS both on matching precision and the reduced number of searching points，which enhances point searching in small range effectively，and the hardware structure mapping to the algorithm is easy to be implemented at the same time. The algorithm is also very fit for Variable Block-Size Integer Motion Estimation.