The present invention provides a main group metal complex, or pharmaceutically acceptable salt, solvate, non-covalent bond compound or prodrug thereof, which is composed of planar tetradentate Schiff base ligands and p-block main group metal ions. The main group metal complex can be conveniently prepared, and shows high cytotoxicity to a variety of cancer cell lines and has selective killing effect. The pharmaceutical compositions or pharmaceutical preparations prepared from the main group metal complex according to the present invention can be used for treatment of tumors. The main group metal complex also has fluorescent properties and can be used for fluorescent labeling.