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Sand layer is a common covering material on the surface of earth. The sample can provide more information for geological analysis in the area. Sand particles were carried by water and wind easily. Therefore, the shallow sample obtained by traditional cutting ring method would lose some important characters. For the high fluidity and low cohesive of sand, the traditional cutting ring sample method cannot collect the samples from the length greater than 20cm with continuous layers information. A new sample drilling technology with flexible tube mechanism was proposed to resolve this problem. It was composed by flexible tube which was fixed in the auger. The sample drilling technology had ability to increase coring length and protect layers. The contact principle and disturbance between the coring drill and sand were analyzed. Based on the simulation results analysis, the reasons for the failure of continuous sampling were revealed. An experimental bench was built to test the difference between the traditional cutting ring and flexible tube drilling method on sampling rate. The results showed that the coring rate was decreased by 10.4% and increased by 16.4% to the flexible tube and traditional cutting ring, respectively. The sampling rate and efficiency of flexible tube were much higher and less adverse the sequence of sand layers. The coring rate of flexible tube was increased from 13.08% to 84.08%.