In order to cope with the difficulty in maintaining the borehole verticality and core recovery due to great alternation of strata, liquefaction of soft strata and sand, poor cementation and loose structure of sand encountered in drilling of the standard 200m geo-technical investigation boreholes in the Xiongan New Area, comprehensive measures such as proper configuration of the drilling string, optimization of drilling parameters have been adopted to prevent drilling deviation. At the same time, effective technical measures such as dry core drilling in loose strata, isolation in core barrels, diversion of the mud pump discharge for core ejection have been adopted to ensure the drilling quality, leading to very obvious technical results.