Abstract: Exploration is of vital importance for onshore petroleum industry in China at present. In future deep and ultradeep wells will be increased by a bigger margin because rich oil and gas resources in deep formation have not been proved yet according to the second national oil and gas resource evaluation. So the onshore petroleum industry faces the arduous task of drilling deep and ultradeep exploration wells with high quality and short time. This paper introduced the basic situation of deep well drilling onshore, showed that deep and ultradeep exploration well drilling in new tracts could not meet the requirement of existing development with onshore petroleum industry. Analyzed the difficulties of deep exploration well drilling and discussed the solution for the difficulties and gave suggestions also.