The invention discloses an RNAi carrier and the application. The carrier contains CMV enhancing factor and the recombinant carrier of tRNAlys promoter in the carrier skeleton with a plurality of clone site; the CMV enhancing factor is located on the upstream of tRNAlys promoter in the carrier; the GenBank number of the CMV enhancing factor is 2828971; the GenBank number of tRNAlys promoter is 140508. The experiment proves that the carrier can restrain the target gene expression effectively and especially in the transducer cell after the downstream of tRNAlys promoter is inserted code DNA for target gene siRNA in the RNAi carrier, so the gene therapeutic medicament restraining the target gene expression is made by the RNAi carrier. The invention shows an important effect in the biological medicine field and in the gene function research.