The invention discloses a sliding rail structure for installing special-shaped space trusses. The sliding rail structure comprises a set of sliding rails which are arranged side by side and a bearingbeam structure used for supporting the sliding rails. The sliding rails are arc-shaped rails. The bearing beam structure is a combined sliding beam which comprises I-steel, a cushion block and a supporting steel plate which are sequentially arranged from bottom to top. A rail pressing plate used for positioning the arc-shaped rails is arranged on the supporting steel plate. Sliding shoes and crawlers used for driving the sliding shoes to slide are arranged on the arc-shaped rails. The construction process for installing the special-shaped space trusses comprises the following steps that (1) the truss in a sliding area slides towards a middle arc from the two ends; and (2) the trusses in other areas are assembled on the ground, then hoisted to be assembled, welded and connected, and then are slid to a specified position. Construction is easy and convenient, the cost is reduced, and the construction period is shortened.