A high efficient sequential similarity detection algorithm (SSDA) is proposed compared with the traditional mould board matching algorithm. SSDA is improved such as using sequence instead of fixed thresh. old, dot sampling, coarse and fine matching combination so as to increase calculation speed further. Based on this, Visual C++ 6.0 is used to implement the algorithm programming. Experimental results show that the algo. rithm has faster calculation speed and less matching error comparing with traditional algorithm.