Abstract: The mechanical structure and performance indexes of 17″(φ426) high-resolution pipeline MFL detector is introduced. It is pointed out that this detector's accessibility is its key index in mechanical performance. Existing problems have been identified during its application in certain natural gas pipeline networks in Shaanxi Province and Northeast China respectively, including insufficient support, severe abrasion of leather cups and susceptibility to unexpected operation suspension. Accordingly, several countermeasures are taken, (1) higher rigidity springs are deployed to increase the supporting forces of the first row supporting wheels, however, this method is less satisfactory, (2) annular steel brush or similar supports are served as the supporting system for battery-driven train to form a running state of detector far superior than with supporting wheels as supports and (3) the simplest and easiest way is to enhance the supporting forces through changing cups' shape, deploying the cups with structures that can provide higher supporting forces, or increasing the number of cups. Desirable performances have been observed for these methods.