An HIV vaccine containing composite virus for preventing and treating AIDS and/or HIV infection is prepared through the codon optimization to the nucleotide sequence of the amplified HIV gag gene, and using the modified gag gene (mod.gag) as the vaccine gene to configure and obtain the recombinant viruses rAd5-mod.gag, rAd5/F35-mod.gag and rAAV/-mod.gag, which have high cellular and humoral immunoresponses. A combined immune vaccine and its scheme are also disclosed.