The invention discloses a DC cell and a targeting immune cell population, and a preparation method and application thereof. The preparation method of DC cells includes the steps of: conducting first induced differentiation culture on mononuclear cells in order to obtain immature DC cells; transfecting the immature DC cells by using BA46 antigen mRNA, so as to obtain transfected immature DC cells; and conducting second induced differentiation culture on the transfected immature DC cells, so as to obtain mature DC cells, wherein the mononuclear cells are isolated from mononuclear cells of peripheral blood of a sample. The method can prepare DC cells safely and efficiently, has a low cost and high efficiency, and can effectively solve the problem of cytotoxicity. The method can be effectively used for immune cell treatment or stimulation of lymphocytes derived from a same patient to produce a targeting cell population containing a large amount of CTL cells, and then the cell population can be used for tumor immunotherapy to reach better effect.