Metabolism alteration is one of the hallmarks of cancer cells. Although several studies have demonstrated that glycolysis played important roles in the progression of nasopharyngeal carcinoma (NPC), the functions of specific metabolism-associated genes remain largely unknown. In this study, it was found that Pyruvate dehydrogenase B (PDHB), which catalyzed the conversion of pyruvate to Acetyl-CoA, was downregulated in NPC cells. Forced expression of PDHB in NPC cells inhibited cell growth and migration, while knocking down the expression of PDHB promoted the growth, migration, and tumorigenesis of NPC cells. Mechanism study showed that PDHB inhibited ERK signaling and cell growth driven by RasV12. Collectively, our study demonstrated the suppressive roles of PDHB in the progression of NPC, and restoring the function of PDHB might be a promising strategy for NPC therapy.