Lunar exploration plays a huge role in enhancing China’s comprehensive strength in all aspects. At present, the researches on lunar sampling are focused on designing and manufacturing the sampling devices instead of the interaction between sampling device and lunar soil. Compared with the Earth’s soil, the different conditions and environment during the formation process make the lunar soil become more special in mechanical properties. During the thin-walled cylinder penetration experiments with lunar soil simulation two phenomena (including lunar soil retention and lunar soil adhesion) were observed, and it was indicated that besides the traditional theory of friction, the theory of maximum shear strength also could be used in analyzing the interaction between sampling devices and lunar soil. Through analyzing of experimental phenomena and data, maximum shear strength theory is closer to actual practice than friction theory. As a result, the maximum shear strength theory is introduced to an existing lunar spiral drilling theoretical model, according to the calculation results, the spiral critical speed based on maximum shear strength is lower than that based on friction, which means lower energy consumption for lunar sampling devices.