The invention discloses a downburst identification calculation method based on a near-ground divergence field, which comprises the following steps: firstly, extracting a reflectivity factor and radial speed information of convective echoes detected by a Doppler weather radar, carrying out quality control to obtain speed data and reflectivity factor information after quality control, and then using a linear least square method, obtaining the divergence of multiple elevation angles through calculation, obtaining the distribution of the multi-elevation-angle divergence of the preliminarily deleted convective echoes through a set distance threshold value and a reflectivity factor threshold value, extracting the convergence of the convective echoes and the vertical distribution of the radiation on the basis, and analyzing the space structure of the convective echoes; and obtaining a downburst occurrence probability based on a divergence threshold established by typical downburst examples in warm seasons. According to the method, the defects of downburst monitoring, forecasting and early warning can be overcome, and the requirements of sensitive users for monitoring downburst and forecasting and early warning disastrous gale generated by the sensitive users are met.