CD4⁺T cells play an important role in regulating adaptive immune responses to various inflammatory responses. Parental T cell populations can differentiate in response to different cytokines into at least four subpopulations: Th1, Th2, Th17, and Treg cells. These differentiated T cells participate in various immune responses and have different roles and functions in oral cancer and precancerous diseases. The Th1/Th2 balance, the Th17/Treg balance and the occurrence and development of oral cancer and precancerous diseases are related to immune imbalances. Reversing these T cell imbalances and strengthening the patient's autoimmune function may prevent or even reverse the progression of oral and precancerous diseases. This paper reviews the research advances on the CD4⁺T cell balance in oral cancer and precancerous lesions.