In order to protect Gao Yan, Empress Dowager Hu took him into her palace, and always tasted the food that he was served to make sure it was not poisoned. However, Lady Lu urged Gao Wei to execute Gao Yan, and Gao Wei, after consulting Zu, who agreed with Lady Lu, decided to do so. Later in the year, when Gao Wei visited the secondary capital Jinyang (晉陽, in modern Taiyuan, Shanxi), he took Empress Dowager Hu and Gao Yan with him. One day, he informed Empress Dowager Hu that he would take Gao Yan hunting the next morning. Just after midnight, he sent messengers to summon Gao Yan, and while Gao Yan was suspicious, he headed for Gao Wei's palace—and on the way, he was seized by Liu and suffocated. He was buried inside Daming Palace (大明宮), and while he had four posthumous sons, they were all executed after their birth. In spring 572, Gao Wei, in order to defuse Empress Dowager Hu's mourning, posthumously honored Gao Yan "Emperor Gong'ai of Chu," and honored Gao Yan's wife Princess Li "Empress of Chu." He also posthumously adopted his own son Gao Ke (高恪) into Gao Yan's line and, after Gao Ke also died shortly thereafter, posthumously adopted Gao Shijun (高世俊), the grandson of his uncle Gao Yān (高淹, note different tone) the Prince of Pingyang into Gao Yan's line.