The incidence of portal vein tumor thrombus (PVTT) is high with poor prognosis. It is the bottleneck to improve the overall efficacy of liver cancer. The existing treatment methods for PVTT include surgery, radiotherapy, transcatheter arterial chemoembolization and systemic therapy, among which radiotherapy is one of the fastest-growing fields in recent years. New radiotherapy techniques, such as three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), stereotactic body radiotherapy (SBRT) and proton beam therapy (PBT), can significantly increase the therapeutic dose and protect normal liver tissues, which can proceed throughout the whole treatment process of liver cancer complicated with PVTT, and play a critical role in further enhancing treatment efficacy of PVTT when combining with alternative treatments. In this article, recent progress in radiotherapy for liver cancer complicated with PVTT was reviewed.