This randomized controlled clinical study aims to evaluate the effect of Modified Huanglian Wendan Decoction on oxidative stress in patients with metabolic syndrome. A total of 180 patients with metabolic syndrome from The First Affiliated Hospital of Heilongjiang University of Chinese Medicine will be assigned to a control group or an observation group at a 1:1 ratio. Participants in both groups will receive lifestyle intervention and standard therapy, including antihypertensive, hypoglycemic, and lipid-lowering treatment. Participants in the observation group will additionally receive Modified Huanglian Wendan Decoction for 3 months. The study will compare changes in oxidative stress indicators, obesity-related parameters, blood pressure, glucose and lipid metabolism, and insulin resistance before and after treatment.