Abstract: The deeply acidizing technology of multilevel injection with viscous HCl acid, oily viscous liquid and mud acid viscous was succeed according to the point of well L-4 in Qingxi, Yumen Oilfield that reservoir is fractured tuff conglomerate pool, well depth is 4552m,formation pressure is 56.64MPa, and high skin factor is 107.73. After the technology has been implemented in well L-4,the yield was ascended from 58m3/d to 256m3/d。The successful test have important guidance and use for reference to formation reform in fractured special pool in Qingxi, Yumen Oilfield.