The invention belongs to the field of medicines, and particularly relates to a pharmaceutical composition containing an IL-15 cationic liposome compound and a celecoxib liposome as well as a preparation method and application of the pharmaceutical composition. In the pharmaceutical composition, the IL-15 cationic liposome compound is a delivery system of a folic acid PEGylation DOTAP cationic liposome nuclear transport gene drug, which is designed by taking plasmid DNA (pcDNA3.1/IL-15) capable of editing and releasing a cell factor IL-15 as a gene drug, after the IL-15 cationic liposome compound and Celecoxib liposome which is released in a targeted manner in TIME are used in a combined manner, Celecoxib promotes NK-cells to be recruited into a tumor microenvironment, infiltration of the NK-cells is greatly improved, IL-15 factors promote proliferation and activation of the NK-cells in the tumor microenvironment, the number of Treg cells is remarkably reduced, the tumor microenvironment is changed, the immunosuppression is relieved to a certain degree, the two components are combined for use, so that the inherent immune anti-tumor effect can be better played, and the safe and low-toxicity synergistic tumor immunotherapy effect is played.