Due to the long-term impact of natural and human-induced damages, rammed earth sites have suffered severe deterioration. Evaluating the current preservation state of these sites, effectively allocating resources, and implementing appropriate conservation measures are of paramount importance. Accordingly, this study investigates 25 typical rammed earth sites in Gansu Province to establish a quality evaluation system. The combined weights of evaluation indicators were determined using FAHP, coefficient of variation, entropy, and CRITIC methods, followed by TOPSIS-based scoring to rank the preservation status of the sites. Analysis of rammed earth sites diseases development and quality evaluation results, along with global sensitivity analysis of five distinct weighting methods using Sobol' and FAST methods, confirms the applicability of the combined weighting-TOPSIS approach for rammed earth sites quality evaluation. The results indicate that the quality of rammed earth sites in different regions follows the order of the Tang > Han > Song > Ming > Qing Dynasty. Regardless of the architectural form, the quality of rammed earth sites in arid areas is the best. The three rammed earth sites of JQMG, GTMG, and MCCZ show obvious signs of deterioration and damage.