The resource exploration is gradually developing into deep exploration in China. Due to the vast territory of China， the strata encountered are quite complex and diverse， which brings great difficulties to the exploration of deep resources. Wire-line coring has become one of the commonly used coring methods in deep resource exploration due to its advantages of “four high， three low and two good”. However， there are still some shortcomings such as low core recovery rate in complex strata and failure of pipe salvage. In order to improve the core recovery rate of wireline coring drilling tool in complex formation， the structural optimization of the cutting mechanism of S75 drilling tool was carried out， and the dynamic simulation was carried out by ABAQUS. The results show that the improved drilling tool has reasonable size and compact structure. It can realize the coring work in complex strata by using a set of drilling tools，has all-strata self-adaptive ability; and has the advantages of avoiding the replacement of drilling tools when drilling loose， soft， hard and brittle strata， and effectively avoiding the failure of internal pipe fishing.