The present invention discloses a method for characteristic string matching based on discreteness, cross and non-completeness, comprising the steps of: A. a user setting discrete number, cross number and non-complete number in the user interface, or an information processing device automatically setting the discrete number, cross number and non-complete number, and inputting the retrieval keywords; B. the information processing device performing the characteristic string matching based on the three characters, with the discrete number, cross number and non-complete number set in step A as matching constraints, for a designated text according to the keywords input by user, and output the matching result of one of the eight retrieval modes, including precise retrieval, discrete retrieval, cross retrieval and cross and discrete retrieval, non-complete retrieval, discrete and non-complete retrieval, cross and non-complete retrieval, discrete and non-complete retrieval. With simple, flexible and convenient operations, the method consistent with the invention realizes a novel operation of information retrieval and provides eight information retrieval modes capable of qualitative retrieval, error tolerant retrieval, and automatic parameter setting retrieval.