Simultaneous detection and location system of lightning optical and electrical signals based on DSP system were used to detect the optical and electrical signals simultaneously in Hangzhou, August, 2009. The detected data are analyzed statistically by time domain characteristics, and statistical results on initial time difference, peak time difference, rise time difference and pulse widths difference between the optical and electrical signals are obtained. The results show that the lightning optical signal is always delayed from the electrical signal on onset and peak time, and the optical pulse rises more slowly to the peak and its pulse-width is broader. The four characteristics of in-cloud flash are all larger than that of Cloud-ground flash. At last, based on fuzzy mathematics, and the above four characteristics as the fuzzy recognition characteristics, fuzzy membership function is established, by which the pattern recognition of lightning is researched and the recognition rate achieves 95%.