The invention discloses a transient power angle stability margin calculation method and system based on artificial intelligence, and the method comprises the steps: carrying out the grouping of a sample concentration mode according to the total active power of a load, the DC power of each loop, the transient power angle stability margin and a leading mode, and selecting a mode with the minimum intra-group stability mode difference index as a central mode; estimating the stability margin of the intra-group mode based on the central mode, optimizing estimation parameters, taking the central modewith a high mode proportion satisfying the estimation precision as a reference mode of a stability margin calculation model, and generating all reference modes of the stability margin calculation model through a subdivision sample set mode; taking a reference mode with a small mode difference index as an effective reference mode for calculating the stability margin of the mode in the sample set;and considering the mode difference index, performing weighted average on the stability margin estimation value based on the effective reference mode to serve as a mode stability margin calculation value in the sample set, and calculating the stability margin of the new mode by adopting a verified stability margin calculation model.