The bitter active ingredients in functional foods have antioxidant, anti-inflammatory, and metabolic regulation effects, but their poor taste affects consumer acceptance. Therefore, this paper systematically expounds the mechanisms of bitterness production and signal transduction mechanism through literature survey, and discusses the development of bitterness suppression technologies and the application of new bitterness suppressants. This paper summarizes the previous studies on the mechanisms of bitter taste transduction and found that the activation of bitter receptors leads to an increase in intracellular Ca2+ level, releasing neurotransmitters and generating bitter taste, and inhibiting Ca2+ levels provides a new idea for bitterness suppression technology. Additionally, the paper outlines three main mechanisms of bitterness suppression: taste interaction, bitter taste receptor masking, and inhibition of bitter receptor cells. On this basis, this paper summarizes traditional bitterness inhibitors commonly used in food processing and the newly discovered bitterness inhibitors in recent years, particularly the novel bitterness-suppressing peptides extracted from natural animal proteins that block bitter signal transduction to reduce bitterness and improve product acceptance. In recent years, bitter inhibitory peptides derived from animal proteins like chicken, beef, and fish have been continuously reported. By comparing different bitterness suppression technologies, this review concludes that blocking the binding of bitter substances to human bitter receptor cells is a promising bitterness inhibition technology, which can not only effectively reduce bitterness intensity but also retain the activities of functional components. The results of this study help promote the application of bitterness inhibitors in bitter foods and provide a theoretical reference for improving the acceptance of functional foods.