Abstract: Pipeline carbon fiber composite material repair, as a novel repair technology, is widely applied in fields such as oil and gas transportation and storage. However, due to the high attenuation, anisotropy, and multi-layered structure of the composite material repair layer, ultrasonic non-destructive testing (NDT) becomes challenging. To solve the above technical problems, this paper proposes a linear C-scan imaging method based on acoustic ray tracing. By accurately calculating the array ultrasonic focusing laws, high-resolution and high-precision imaging of internal defects in the composite material repair layer is achieved. Experimental tests on typical defect specimens demonstrate that both interlaminar delamination and interface delamination defects can be effectively detected. Compared to traditional homogenization methods, the defect missed detection rate is reduced by 25% and the average defect quantification accuracy is improved by 46.6%. These results indicate that array ultrasonic testing technology is fully applicable to the detection of composite material repair layers in pipelines, providing an effective non-destructive testing solution for the quality assessment of pipeline repair layers.