The invention discloses a recombinant oncolytic 
vaccinia virus and a preparation method and application thereof. The 
thymidine kinase (TK) region of the 
virus comprises a coding sequence of a PD1 full-length 
antibody shown in the formula of SEQ ID NO.1. Through effective combination of the anti-tumor effect of 
gene therapy and the oncolytic effect of 
virus treatment, the oncolytic 
vaccinia virus for efficiently expressing the PD1 full-length 
antibody gene is prepared. When the oncolytic 
vaccinia virus produces the oncolytic effect of splitting 
tumor cells, the PD1 full-length 
antibody is efficiently expressed, the activity of PD1 on the surfaces of T cells is inhibited, the 
T cell immune response is activated and the dual antitumor effects are produced. Compared with the 
single gene therapy or 
viral therapy, the method using the recombinant oncolytic vaccinia virus improves the effects of killing malignant 
B cell lymphoma. Through virus replication-
related gene deletion, the TK regionof the vaccinia virus 
genome is deleted so that specific replication of the viruses in the abnormally proliferating 
tumor cells is ensured and the viruses can not replicate in normal cells, so that the safety of the oncolytic vaccinia virus vector is greatly improved.