This paper introduces the structure， main features and application of Geoprobe7822DT， Geoprobe 8040DT and Geoprobe 3230DT direct push soil drilling rigs， and compares them with other types of similar sampling rigs. Analysis is conducted on their inadequacies in quicksand sampling such as insufficient wall protection， poor overall stability， and easy drill pipe damage with suggestions put forward for further improvement and use of the direct push soil drilling rigs．