Lithology changes obviously in volcanic strata and the physic mechanics character of rock differs a lot. Corresponding diamond bit parameters are selected according to the physic mechanics character of rock, the service life and drilling efficiency can be greatly improved with good drilling effect and economic benefit. The paper illustrated the statistic and analysis on the service life and drilling efficiency of diamond bits with different drilling parameters in several volcanic strata, and put forward the selection principles and selection methods of diamond bit technical parameters suitable for volcanic strata.