The distribution of the microseismic events induced by hydraulic fracturing is used to study the geometry of the fracture growth. Therefore,it is important to obtain accurate locations of microseismic events. Detecting the accurate locations of microseismic events relies on an accurate velocity model. Because of the trade-off between the event locations and velocity model,the solution of simultaneous inversion method is easily trapped in the local minima. Neighbourhood algorithm(NA)is a global optimization algorithm and has more power to escape from local minima. This study applies the NA to the simultaneous inversion of source location and 1D velocity model for single well monitoring. The NA is used to search 1D velocity model firstly,and then locating the source parameters with the grid search method. Finally,the travel time residuals of the location are used to evaluate the 1D velocity model derived by the NA. Both numerical tests and field data are applied to this method in this paper. Results indicate that the joint NA and grid search method can avoid local solutions and obtain reasonable event locations and 1D velocity model.