Optimized design was made on middle-shallow stratum exploration well for environmental protection well drilling in Daqing oilfield. Starting with the design of casing program, related preventive and improving measures were formulated for the designs of drilling fluid, drill assembly and well cementing. The improved casing program increased the safety in drilling construction with environmental protection, especially for deep water. The reservoir potential damage was studied; the action principle, application and the effect of well protective technology were analyzed. The after-effect tracking showed that there was no water and environment pollution in the 15 oil and gas wells drilled in 2010 with deep surface casing in middle-shallow stratum.