Qiangtang basin is an area with the lowest annual mean ground temperature and a relatively thick frozen soil layer in the Qinghai-Tibet Plateau, the hydrogeology and engineering geological environment are extremely complex. Because of low exploration degree in Qiangtang basin, there are few real drilling data of deep hole drilling, the study on rock physical and mechanical properties of deep rock strata in this area is lack. Therefore, combining with geophysical well-logging technology, coring and tests measuring results, the analysis is made on rock physical and mechanical parameters of the formations in QK-7 borehole drilling process for natural gas hydrate exploration, and the summarization and exploration are carried out for mud technology of borehole wall stability in extremely complex tundra abnormal pore water pressure in order to provide the practical experience for the smooth implementation of deep drilling in the strategic development of oil and gas resources in Qiangtang basin.