This invention unveils an optical microphone utilizing diamond cantilevers and its associated acoustic sensing system. The core component is a diamond cantilever, featuring a diamond diaphragm with a centrally located U-shaped groove. The manufacturing process involves several key steps: initially preparing the diamond diaphragm using silicon in a chemical vapor deposition setup, where methane and hydrogen are reacted under specific temperature and pressure conditions to form a diamond polycrystalline film on the silicon. This film is then separated from the substrate to create the diaphragm. Subsequently, a U-shaped groove is crafted on the diaphragm by applying a dry etching template and etching, resulting in the formation of the diamond cantilever, with a thickness ranging from 10 to 100 m. This method establishes a novel approach to creating sensitive and durable optical microphones.