Disclosed are a sustained release suspension containing dezocine analogue ester and a preparation method therefor. According to the present invention, an injectable oily auxiliary material which may pharmaceutically serve as a sustained-release depot and an excipient are selected, and micronization technology is used jointly with high pressure homogenization technology and an anti-solvent technique to prepare an injectable long-acting suspension. The main components of the suspension are a compound represented by formula (I), the injectable oil, and the like.
