The invention provides a special compensator for a maintenance-free pipe rack system. The compensator is located on a compensation mechanism mounting frame at least in the length direction of a pipeline; the compensation mechanism mounting frame is mounted on the ground; two ends of the compensator are respectively connected with an upstream pipe body and a downstream pipe body. The compensator is characterized by comprising an inner movable sleeve, an outer sleeve and an end pipe; the end part of the inner movable sleeve is fixed at the lower middle part in the outer sleeve; the end part of the end pipe is fixedly fitted to the inner wall of the top end of the outer sleeve, thus forming a three-layer sleeve structure. The special compensator for the maintenance-free pipe rack system has the outstanding characteristics of no thrust, large compensation distance, low operation cost and the like, and can meet the urban heating requirement.