Abstract: A five-membered heterocyclic oxocarboxylic acid compound and the medical use thereof are described. Specifically, provided are a compound as represented by formula (I) and a pharmaceutically acceptable salt, prodrug, hydrate, solvate or crystal form thereof, and also a method for preparing the compound, a pharmaceutical composition containing the compound, and the medical use thereof as a secretion regulator of type I interferon, especially as a STING agonist, and the preparation of a drug for preventing and/or treating diseases related to type I interferon.