The invention discloses a building method of a silkworm BmNPV Polh+Bac-to-Bac rhabdovirus expression 
system, comprising: taking silkworm 
wild type BmNPV 
genome DNA as the template; respectively taking P10-upF / P10-upB and P10-downF / P10-down B as a primer PCR for amplification to obtain p10-up and p10-down; after processed, inserting into 
BamHI-PstI-
HindIII locus in pUC 19 to obtain recombinant 
plasmid pUC19-p10-up-down; using pUC-19-p10-up-polh-down, 
liposome lipofectin and MilliQ H2O to prepare 
DNA-Lipofectin mixed liquor; adding the mixed liquor into BmN cells for cultivating; collecting 
transfection cell supernatant; inoculating BmN cells, and recovering a polyhedral body; extracting 
virus DNA from the polyhedral body and electrically converting DH10 beta competent cells; screening locus ceruleus and cultivating; after cultivating PCR positive bacterial plaque, extracting 
macro-molecular DNA to transfect to the BmN cells; separating to obtain helper plasmids from DH10Bac 
culture bacteria of AcMNPV Bac-to-Bac; converting the helper plasmids into E.coli DH10 beta containg Ploh+BmBacmid; and screening the DH10 beta 
bacterial strain of the helper 
plasmid containg Ploh+BmBacmid. The invention can produce 
recombinant virus capable of infecting by eating with mouth, and 
recombinant virus does not need to infect by intracutaneous 
inoculation, thus improving the production efficiency of the silkworm rhabdovirus expression 
system.