Double-plasmid expression system capable of producing virus-like particles containing large segments of RNA

The invention relates to a double-plasmid expression system capable of producing a virus-like particle packing large-fragment RNA, which belongs to the field of biotechnology. The double-plasmid expression system capable of expressing the virus-like particle containing large-fragment RNA consists of a plasmid PET-MC and a plasmid pACYC-X, wherein the PET-MC is constructed by integrating pET-28(b) with mature enzyme protein of phage MS2 and capsid protein cDNA, and the pACYC-X is constructed by integrating a 19mer packing site of the phage MS2 and the cDNA of target RNA. The invention has the advantage that the virus-like particle expressed by the double-plasmid expression system contains long-fragment RNA. Different target fragments to be amplified by virus are constructed together to form a chimera which is packed into the virus-like particle, thus the virus-like particle can be taken as a multi-target nucleic acid standard and a quality control material applicable to simultaneous detection of a plurality of viruses for the same specimen so as to save cost and simplify operation procedures.