Abstract: By using a nonlinear method-genetic algorithm, the residual error, that is, the difference between the observed time and the theoretical time, is solved by genetic algorithm to obtain the results of non-enclosed seismic events, which is due to uneven distribution of stations. At the same time, we use the simplex method in MSDP to get the results of non-enclosed seismic events. The two location results were compared respectively with cataloging results. The results show that the genetic algorithm is more close to the result of the catalogue, and the two parameters of the earthquake time and the epicentral location are more accurate, so that the positioning accuracy of the non-enclosed seismic event is improved.