The latest physicochemical pretreatment technologies to improve the emulsifying properties of proteins and the corresponding mechanisms were summarized, including the physical modification such as ultrasound, high pressure homogenization, extrusion cooking, and swirl cavitation, and chemical modification methods such as pH shifting, phosphorylation modification, and enzymatic modification. Moreover, this review also included the synergistic effects of the above methods to modify proteins and the related mechanisms and the future research prospects of the protein modification.