Casticin is one of the effective ingredients of fructus viticis. Most studies have shown that casticin has a strong anti-proliferation activity against various tumor cells. However, its anti-tumor effect and molecular mechanism in nasopharyngeal carcinoma remain unclear. In this study, we demonstrated that the casticin selectively inhibited the proliferation of 5–8F cells in vitro. Further analysis revealed that casticin treatment significantly increased sub-G2 phase and incited pyroptotic process. Moreover, we demonstrated that PKR participated in in regulating the process of GSDMD-dependent pyroptotic tumor cell death. PKR knockdown alleviated the activation of JNK pathway and the expression of its downstream proteins, including cleaved caspase-1, GSDMD-N, interleukin-1β. These findings indicate that PKR/JNK/NF-κB signal is essential for casticin-induced caspase-1 inflammasome formation and inflammatory cytokines release in 5–8F cell.