To explore the sperm morphology and physiological characteristics of Hapalogenys mucronatus andenhance the fertilization rate of artificial reproduction, sperm structure was observed using scanning electronmicroscopy and transmission electron microscopy under varying gradients of salinity, pH, and temperature. Ouraim was to investigate the relationship between the rapid movement time, life span, and environmental factors ofH. mucronatus sperm. The results showed that the sperm of H. mucronatus consisted of three parts: the head,middle part, and flagella. The head of the sperm was nearly spherical or ellipsoidal, with a diameter of (1.56±0.05)μm. Chromatin in the nucleus was highly concentrated, and the nuclear membrane was close to the plasmamembrane without the acrosome. The middle part was mainly composed of a sleeve cavity and a centriole complex.The flagellum is slender and has lateral fins, which is a typical “9+2” microtubule structure. The suitable salinityrange for Hapalogenys mucronatus sperm was 22–28, and the sperm lifespan reached a maximum value of 425 swhen the salinity was 26. The optimum pH range was 7–10. Sperm motility was the strongest at pH 7, and spermlifespan reached a maximum of 430 s. The suitable temperature range is 18–26 ℃, and the longest sperm life is427 s when the water temperature is 22 ℃. It is suggested that the optimum water environment conditions for thefertilization of eggs and sperm of H. mucronatus are salinity 24–26, temperature 20–22 ℃, and pH 7–8.