A pyrrolidine derivative serving as a PPAR agonist, and applications thereof in treating diseases of pathways related to a PPAR receptor, such as nonalcoholic steatohepatitis, complication fibrosis, insulin resistance, primary biliary cholangitis, dyslipidemia, hyperlipemia, hypercholesterolemia, atherosclerosis, hypertriglyceridemia, cardiovascular diseases, obesity, and other diseases. Specifically, the pyrrolidine derivative is a compound represented by formula (I) or a pharmaceutically acceptable salt thereof.