Unidrill SRF series desanders, self-developed by Beijing Unidrill Technical Co., ltd., mainly used to recycle the slurry essence in piling constructions of circulation& counterflush drilling and shied constructions of slurry balanced, can decrease the slurry discharge, cut tool-sticking accidents, and improve the drilling efficiency. Double screen mesh was adopted in filter system to improve working efficiency by 50% compared with the traditional single mesh one. Meanwhile, our desander has the properties of simple operation, easy maintenance as well as outstanding cleaning and purifying ability, long service life and high reliability.