In view of few systematic studies on selenium-rich ceramics, especially the controllable preparation, analysis, and characterization of selenium-rich ceramics, the release rule of selenium elements is rarely reported in the literature either. Therefore, this paper uses ordinary soil samples as raw materials to simulate the selenium-rich ceramics' synthesis by adding a selenium source to study the selenium content of selenium-rich ceramics and the dissolution law of selenium. With the increase in selenium added, the selenium content in selenium-rich ceramics increased from 13.3 to 112.4 ppm. When selenium pottery was soaked in water, the release amount of selenium was gradually increased with the extension of soaking time. With the increase of sintering temperature, the selenium content in selenium-rich ceramics was decreased from 30.1 to 18.2 ppm, and the selenium release amount was decreased from 0.13 to 0.06 ppm when immersed in water for 48 hours. Therefore, by adding a selenium source, the selenium content in the selenium-rich ceramics can be controlled accurately and the leaching amount of selenium element is balanced and stable over time.