Zhang Jian’s automated 2D multi pass velocity dealiasing algorithm based on the horizontal continuity of velocity fields is improved in this paper. In Zhang Jian’s method, a set of initial reference radials and gates are obtained by finding the weakest wind region, and then with these initial reference radials and gates, the continuities among adjacent gates are checked and the aliased velocity values are corrected. However, it is hard to precisely obtain reference radials and gates because real wind field is interfered by meso or small scale system, and isolated echo zone, which will influence the velocity dealiasing process greatly. Therefore, the improved algorithm is proposed for this problem. In the continuous detection processes, the aliased velocity suspected boundaries are determined, and then the aliased boundaries and velocity regions are identified. After that, an extend neighborhood scheme is applied to correct the aliased velocity gates in the aliased velocity region in the aliased velocity revision process. In addition, by lots of radar volume scan experiments, it is found that the discussed method is effective in velocity dealiasing, which is significantly better than Zhang Jian’s scheme and WSR 88D scheme.