High-power laser delivery in infrared optical fiber has received much attention due to the urgent needs in the fields of national defense security, biomedicine, advanced manufacturing, and so on. In recent decades, there has been extensive research aimed at enhancing the capabilities of infrared laser power delivery through the purification of infrared glass or the optimization of fiber structures. This article provides an overview of common passive mid-infrared (MIR) optical fibers with numerous glasses and fiber structures, as well as their characteristics in laser power delivery. This review also highlights potential research directions and analyzes the challenges of passive mid-infrared fibers in the current applications.