An optical fiber connector adapter has a housing, a front sleeve holder, a rear sleeve holder, a sleeve and detachable positioning member. The housing has a cavity, two limiting protrusions and two positioning slots. The cavity and positioning slots are defined in the housing. The limiting protrusions are formed in the cavity. The front and sleeve holders are mounted in the cavity and each has a tube and a mount abutting the limiting protrusions. The sleeve is mounted in the tubes. The detachable positioning member is mounted on the housing and has two stoppers extending respectively the positioning slots to make the mounts clamped between the limiting protrusions and the stoppers. The optical fiber connector adapter with the detachable positioning member may be detached easily to facilitate rework.