Abstract: With the rapid development of tumor immunotherapy in recent years, therapeutic cancer vaccines are attracting increased attention. Compared with personalized neoantigen vaccines, in situ vaccines could form an antigen reservoir in the tumor itself. Subsequently, antitumor immunity is initiated and the response to immune-checkpoint inhibitors of some patients improve without necessitating these patients to undergo the complicated procedures of detecting personalized antigen and customizing and synthesizing antigen peptide. At this stage, the potential of realizing the clinical translation of in situ vaccination is tremendous. In this review, we primarily introduce the mechanisms of radiotherapy and intratumoral immune injection as in situ vaccination and discuss the current status of preclinical study and clinical application of their combination to attract more attention from researchers and clinicians toward in situ vaccination.