According to the requirements of environmental protection and drilling of geothermal exploration and production Well D20 in Xiongan New Area, the research and application effect analysis of the drilling fluid solid control circulation system are carried out. The whole system is composed of a “4+1” modular closed tank body equipped with five-level purification facilities, which can meet the process requirements for treatment of downhole complex situations, such as drilling fluid make-up, storage, circulation, purification, replenishment, dosing, weighting; as well as the environmental requirements for closed-loop circulation. The field application shows that the system can meet the requirements of green exploration and drilling of exploration and production Well D20, but it needs to be further improved in terms of structural design and optimal configuration. Some suggestions are put forward in the hope of providing reference and guidance for the reasonable practicability of system design and configuration and the economy of drilling engineering.