Here, the potential distribution of four famous poisonous weeds, Achnatherum inebrians, Oxytropis ochrocephala, Stellera chamaejasme, and Aconitum gymnandrum, was studied using ecological niche models. Firstly, occurrence records and environment variables were selected using the nearest neighbor distance method and correlation analysis. Next, the ecological niche models were established using maximum entropy (Maxent) to predict the potential distribution areas of the four poisonous weeds. Finally, Matlab and ENMTools were applied to compute the geographical distribution centroid, the average elevation, the percentage of hierarchical distribution areas, the niche breadth, the niche overlap, and the range overlap. The results show that, among the four poisonous weeds, A. inebrians and S. chamaejasme have strongly environmental adaptability. However, the distribution range of A. inebrians is relatively wider, extending from Qilian Mountains to Gannan Grassland, and the geographical distribution centroid is basically on the western side of Qilian Mountains. The distribution range of S. chamaejasme is mainly in southern Gansu, and its geographical distribution centroid mainly locates in the Lanzhou area. O. ochrocephala is mainly distributed in Qilian Mountains, whereas A. gymnandrum is mainly found in Gannan Grassland.