Inflammation and oxidative stress are two major factors that are involved in the pathogenesis of atherosclerosis. A smart drug delivery system that responds to the oxidative microenvironment of atherosclerotic plaques was constructed in the present study. Andrographolide-loaded micelle was assembled from the block copolymer of poly(ethylene glycol) and poly(propylene sulphide) (PEG-PPS) for the purpose of simultaneously decreasing inflammatory response and the level of reactive oxygen species (ROS) to treat atherosclerosis. Owing to the ROS-responsive nature of PEG-PPS, the micelle not only serves as a stimuli-responsive drug carrier to quickly release the encapsulated drug, andrographolide, but also consumes ROS by itself at the pathologic sites, upon which the expressions of pro-inflammatory cytokines are effectively suppressed and oxidative stress is alleviated. Consequently, the andrographolide-loaded micelle demonstrated remarkable therapeutic effects both in vitro and in vivo. In conclusion, the andrographolide-loaded PEG-PPS micelle can synchronically alleviate inflammation and oxidative stress, providing a promising and innovative strategy against atherosclerosis.