Abstract: The open-hole compression (OHC) performance is one of the critical property indices for 3D woven composites in the design and service of connection structures. This paper investigates the warp direction OHC performance of carbon/epoxy 2.5D woven composites, and conducts a comparative analysis with laminate composites of equivalent fiber volume fraction. Using digital image correlation (DIC) technique, the evolution of the minimum principal strain on the material surface under warp-direction compressive loading is analyzed. The results show that the warp-direction OHC strength retention rate of the 2.5D woven composites reaches 72.62%, which is 17.52% higher than that of the laminate composites. The binder yarns inhibit damage propagation along the thickness direction and alleviate the strain concentration around the hole. The maximum strain concentration factor of the open-hole 2.5D woven composites is 7.18, which is 41.62% lower than that of the laminate composites. Under warp-direction compressive loading, the region of high minimum principal strain in the open-hole 2.5D woven composites exhibits an X-shaped distribution along the ±45° direction around the hole. Its extent is constrained by the fiber interlacing structure: in the warp direction, it is limited between the intact weft yarn rows above and below the hole; in the weft direction, it is confined between the intact binder yarn rows on the left and right sides of the hole. The evolution of the minimum principal strain presents a typical three-stage characteristic, demarcated by 10% and 88% of the failure strain. When the applied strain exceeds 88% of the failure strain, the strain concentration factor increases sharply, accompanied by significant local stiffness degradation and damage. In contrast, the laminate composites exhibit continuous local stiffness degradation and damage after the applied strain reaches 44% of the failure strain. At locations where the entire rows of binder yarns are truncated by the hole, the peak value of the minimum principal strain is more than 25% higher than that in other regions, and these are also the sites where initial visible surface damage initiates. The direction of the minimum principal strain on the material surface shows a spindle-shaped distribution symmetric about the hole center. The main failure mode of the open-hole 2.5D woven composites is compression-shear fracture, whereas the open-hole laminate composites are dominated by extensive delamination. This study provides an important theoretical basis for the optimal design of connected structures using 2.5D woven composites.