The invention relates to a controllable genome-modified plasmodium, a recombinant expression vector and the construction method and application of the controllable genome-modified plasmodium and the recombinant expression vector. The recombinant expression vector comprises a gene targeting long homologous arm, a gene targeting short homologous arm, a tetracycline repression protein gene expression cassette, a pyrimethamine resistance gene expression cassette and a target gene expression cassette, wherein the tetracycline repression protein gene expression cassette, the pyrimethamine resistance gene expression cassette and the target gene expression cassette are located between the gene targeting long homologous arm and the gene targeting short homologous arm, and tetracycline operator gene sequences are inserted in multiple transcriptional start sites of a target gene promoter, so that the recombinant expression vector can be used for conditional research of the functions of a certain functional gene in a plasmodium genome. Furthermore, a functional gene expression sequence, corresponding to a target gene, in the plasmodium genome is knocked out by means of the gene knockout technique; meanwhile, the recombinant expression vector is transfected into a plasmodium with genes knocked out, so that the controllable genome-modified plasmodium is obtained; a new technical scheme is provided for further research of the functions of all functional genes in the plasmodium genome, and application prospects are broad.