The loose, broken, collapsed and watersensitive formations are often encountered while drilling in the sedimentary formations, which were mainly dealt with cement sealing and casing cementing in the past with high drilling cost, low efficiency and great labor intensity in the past. Along with the appearance and development of non-solid drilling fluid technology, effective solutions are provided to overcome difficulties in sedimentary rock drilling. The paper introduced the research on nonsolid drilling fluid technology and its application effect in complex sedimentary formation drilling by application example.