Plant proteins offer sustainable and eco-friendly alternatives to animal proteins for various applications. This study aimed to develop pulse protein microgels from lentil and fava bean proteins by protein-polysaccharide segregative phase separation. By adjusting the protein to alginate volume ratio, the mean microgel sizes (D3,2) were controlled at 3, 7 and 15 µm for lentil protein and 3, 7 and 19 µm for fava protein. This fabrication method efficiently produced size-controlled microgels with low energy consumption. The emulsifying properties of lentil protein microgels were further explored. Compared to untreated protein-stabilized emulsions, which exhibited creaming after one day, the microgel-stabilized emulsions showed no creaming after 28 days. Microgels of different sizes stabilized emulsions through distinct mechanisms. Confocal laser scanning microscopy images illustrated that the smallest microgels at 3µm absorbed at the oil-water interface, forming Pickering emulsions and effectively stabilizing emulsions with 25% and 50% oil volume fraction with nearly no creaming after one month of storage. The larger microgels showed reduced emulsifying stability at 25% oil but similar stability at 50%. They dispersed in the continuous phase, contributing to emulsion stability through steric hindrance and a gelling effect. Moreover, emulsions prepared from lentil protein microgel at 25% oil exhibited enhanced viscosity and texture compared to emulsions made with untreated lentil protein at 50% oil. This research provides a strategy to improve the emulsifying properties of plant proteins for their wide applications in food formulations to create stable and healthy low-fat food products.