The invention discloses a tumor targeting metal complex, a synthetic method and application. The synthetic method comprises the steps of connecting a ligand with a substituent group and a targeting molecule, complexing the ligand and metal ions, and synthesizing to obtain the tumor targeting metal complex, wherein the ligand is one of a phenanthroline derivative, a dipyridyl derivative, a benzimidazole derivative, a phenyl-pyridine derivative and a thiophene-pyridine derivative; the targeting molecule is one of biotin, folic acid, integrin, transferrin, cell-penetrating peptide, octa-poly-L-arginine, MUC-1 attached membrane protein, galactosamine, neovascular targeting peptide and a granulocyte-macrophage colony-stimulating factor; the metal ions are ruthenium, osmium, rhodium or iridium ions. The complex obtained by the method provided by the invention can be selectively absorbed by tumor cells, and induces apoptosis of the tumor cells. In a nude mouse tumor-bearing model, the tumor targeting metal complex can image and treat tumors, and the toxicity of organs and tissues is reduced.