Effects of plasma treatment distance on the adhesion properties of carbon fiber composites were investigated, and the association between the distribution of surface physical characteristics on the composites and their bonding properties was discussed. After plasma treatment at different distances, surface morphology of the bonding area was obtained and the roughness distribution model was established. The change in surface physical characteristics directly influences the wettability of the bonding surface and the tensile shear strength (TSS) of the bonded components. When the TSS showed an increase by 19.47% at the treatment distance of 15 mm, metallographic images indicated that the bonding layer was integrated with the composites and the joint in the component was dominated by cohesive failure. When the TSS showed a decrease by 30.72% at the treatment distance of 5 mm, metallographic images indicated that voids and delamination were introduced in the bonding layer and fiber tearing failure mode appeared in the plasma etched area. Moisture‐heat resistance of the bonded components was also considered and a noticeable increase in water absorption was observed in the case of excessive treatment at the distance of 5 mm, which was also related to the distribution of physical characteristics induced by the plasma treatment. Highlights: Surface characteristic distribution of plasma‐modified composites was analyzed.State of resin and fibers on composite surface varied with the treatment distance.Semi‐annular plasma treatment traces appeared in the roughness distribution.The high roughness in the distribution played a key role in bonding properties.Performance degradation due to close treatment was also distribution‐dependent. [ABSTRACT FROM AUTHOR]