Nowadays, the prevalence of obesity is popular all over the world, and the complications causes by obesity have bought heavy burden to both society and family. More trial related to the micronutrient and new metabolism toward obesity are noticed and clinicians hope to find the most common and healthy way to help patients get out of their weight difficulties. The role of vitamin D acting in obesity is increasingly being studied. Although existing experiments have proved that obesity is related to vitamin D deficiency, there are still few studies on its specific mechanism and the influence of vitamin D on obesity through Microbiota-gut-brain. This article will summarize the known mechanisms of vitamin D on adipocytes, inflammatory reaction, and enzymatic and metabolic processes that contribute to obesity and focus on the novel mechanism of vitamin D action on obesity through the Microbiota-gut-brain axis. We set a bridge between vitamin D and Microbiota-gut-brain axis and try to explain its effect from intestinal flora, intestinal barrier and nutrient absorption and insulin and leptin central neurons factors. And we suggest patients and clinicians should pay attention to vitamin D intake in daily life or during weight loss.