Abstract: Thermodynamic analysis of reactions affecting the dissolution of BaS during water leaching, and the effects of leaching temperature, leaching time, and liquid-solid ratio on the presence of water-soluble barium were investigated. The results show that increasing the liquid-solid ratio and leaching temperature can effectively increase the leaching rate of BaS. Part of the dissolved barium will generate water-insoluble barium, and the total formation rate of water-insoluble barium increases with the increase of the leach temperature and time, and decreases with the increase of the liquid-solid ratio.When the leaching temperature is 55 ℃, the leaching time is 60 min, and the liquid-solid ratio is 60, the leaching rate of BaS was 90.13%, the residual rate of BaS was 4.27%, formation rate of BaSiO₃ was 3.14%, formation rate of BaCO₃ was 3.14%, BaS has higher leaching rate, lower residual rate and lower water-insoluble helium formation rate under the process conditions.