The SCIT (Strom Cell Identification and Tracking) algorithm is introduced by means of the dynamic template function method for automatically identifying the linear MCS to locate storm cells, further to calculate RLW (Ratio of Length to Width) of MCS. The method is used in more than 20 different types of convections cases with different thresholds. The results demonstrate that the dynamic template function, average RLW and maximum RLW from SCIT can present the linear status of MCS, which are well correlated in the case of different thresholds. The inconsistency is resulted from that the centroid has not enough representativeness and much less storms cells to cause large fluctuation in average RLW and maximum RLW. Comprehensive analysis results show that the dynamic template function method is more stable and reliable, and coincident with the actual situation.