Well JG-2 is located in Fengshan Town， Jinggu Dai and Yi Autonomous County， Pu’er City， Yunnan Province. The structural location belongs to Jinggu Sag of Simao Basin， and the completion depth is 1829.44m. The lithology of drilling strata are mainly mudstone， sandstone， mud conglomerate， halilith， sylvinite and so on. The mudstone is prone to hydration expansion and spalling， resulting in wellbore collapse hazards. Local loose sandstone is prone to collapse， while halilith and sylvinite are easy to dissolve to form hole enlargement and low salt core recovery rate. In view of the above construction problems， saturated magnesium chloride brine drilling fluid was used when entering the gypsum vein salt formation to successfully complete the engineering drilling and coring tasks. The technical problems such as the dissolution of salt cores such as sylvinite， difficulty to carry coarse particles of salt， bit balling and collapse of loose sandstone were solved. Full salt cores containing the roof and floor part were successfully taken， and high-quality salt cores such as halilith and sylvinite were obtained. The average core recovery rate of the whole well was 97.5% without dissolution. The successful experience of this paper can provide reference for similar potassium salt drilling projects.