The objective of this study is to investigate the mechanism of the modification of pea protein isolate (PPI) by transglutaminase (TG) in combination with dynamic high-pressure microfluidization (DHPM) and to clarify the applicability of the modified PPI in Pickering emulsion. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy showed that the morphology of PPI particles became more uniform after the modification. The degree of crosslinking with TG increased, and the tertiary structure of protein molecules changed. In addition, the surface hydrophobicity and endogenous fluorescence of PPI decreased, the emulsifying properties improved and the average particle size decreased. The Pickering emulsion stabilized by the modified PPI had improved stability and emulsifying capacity, and the best emulsion stability was observed at 120 MPa. TG-DHPM modification could provide a feasible method for the application of PPI in Pickering emulsion. This study provides an experimental basis for the development of high-performance Pickering emulsion systems and is of significant reference value for the functional modification of natural proteins.