For centuries, there has been a group of powerful elite teams that have maintained peace in the vast universe. Each of them has a green energy ring, the green light is the source of their strength, they are called the Green Legion. But suddenly one day, the Green Lantern in many parts of the universe continued to be attacked and killed. It turned out that the evil king Perillex, who had been silent for many years, woke up and wanted to rob the Green Lantern of their green energy source, so he launched a universal hunt for the Green Lantern. At this time on Earth, Hal (Ryan Reynolds Ryan Reynolds), a test pilot with extraordinary talent but pretentious, inadvertently won the green ring of the fallen Green Lantern and became the new Green Lantern guarding the Earth. And its human nature, as human beings, is also a unique breath that other green lanterns do not have. In order to defeat Perillex, protect the earth and save mankind, Hal needs to overcome fear and use his green light energy skillfully. As the Devil King approaches, can Hal defeat the Devil King and become the greatest Green Lantern?