In the field of species identification, the traditional algorithm is based on the BLAST method, which is regarded as the authoritative method, but the method has a series of problems such as complex calculating process, time-consuming, as well as space-consuming. In this study, we propose an improved VSM algorithm based on K-String compositional vector method, and give the alternative norm-format formula in calculating the genetic distance between species in the Banach space for the reference of other scientific researchers. In this study, the computational efficiency and the result of the species identification are the two aspects to determine the properties of the improved method. The conclusion is that the calculating time of improved VSM algorithm based on 2-norm has decreased obviously than that of the BLAST algorithm, in addition, the result of classification demonstrates good consistence and convergence with the comparison result in terms of detection rate.