He originally served as one of Sun Ce's bodyguards, alongside his former comrade in piracy Jiang Qin. When Ce entered Kuaiji, Zhou Tai was made Major with a Separate Command, and given troops to command. Sun Quan took a liking to Zhou Tai’s character, and requested for Tai to be transferred to himself.

Numerous times throughout his career, he saved Sun Quan from danger by risking his own life. Once, while Sun Ce was out fighting Shanyue rebels from the six prefectures, Sun Quan was left in Xuan city with less than a thousand guards. Out of negligence, he did not set up defence posts. Several thousand of Shanyue rebels attacked. By the time Sun Quan mounted his horse, the bandits managed to surround him already. Their weapons, hitting here and there, slashed Sun Quan’s saddle, causing great panic all around. Only Zhou Tai, with spirits roused, defended Sun Quan with his body, emboldening those near him and making them able to fight again. When the bandits were finally dispersed, Zhou Tai was found with twelve deep wounds, which took a long time to heal. Had Zhou Tai not be there on that day, Sun Quan would have perished. This deed was greatly appreciated by Sun Ce, who added the title of Chief of Chunju Prefecture to Zhou Tai.