Chlorella vulgaris, a green microalga, is widely recognized in the food industry for its outstanding nutritional value. This review systematically summarizes the diverse nutritional components enriched in this microalga, including proteins, lipids, carbohydrates, vitamins, pigments, and minerals, as well as the various bioactivities conferred by these components, such as antioxidant, anti-inflammatory, immunomodulatory, antibacterial and antiviral, anticancer, detoxifying, adjuvant antidiabetic, antihypertensive and antihyperlipidemic, neuroprotective, antidepressant, and prebiotic activities. Additionally, the research progress of C. vulgaris in food applications is elaborated, and the current challenges in its commercialization are discussed, including the technological gap in large-scale production that coordinates nutritional composition and low-cost requirements, the unclear mechanisms underlying its nutritional and bioactive effects, as well as safety concerns and policy restrictions associated with synthetic biology applications. Based on these considerations, future research directions are proposed, focusing on the efficient production of diverse nutritional components, the improvement of bioavailability, and the in-depth elucidation of the mechanisms underlying nutritional and bioactive functions.