The invention relates to improvement of radiopharmaceutical yield and application of the radiopharmaceutical yield to the field of nuclear medicine and imaging, in particular to a medical radioisotope labeled P2X7 receptor targeting probe precursor, a targeting probe thereof and application of the targeting probe to diagnosis of neurodegenerative diseases. The structural formulas of the targeting probe are shown as a formula (III) and a formula (IV), wherein R4 and R6 are any one of a hydrogen atom, < 18 > FCH2CH2-and < 18 > FCH2CH2CH2-; r5 is any one of a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and < 18 > F; x is any one of halogen atoms.