Pipeline robots are vital tools for detecting and assessing pipeline damage in complex systems. Incorporating imaging systems into their forward trajectory enables these robots to navigate and observe the internal environment of pipelines. However, this positioning often results in pipeline walls information appearing at the edges of the image sensor, where lens distortions substantially impact the image quality. This distortion reduces the precision of damage detection and complicates the quantification of damage. Additionally, integrating additional imaging systems to observe the walls would substantially increase the robot's payload and volume, which is a critical issue for small-scale pipeline robots. To address these challenges, we developed a miniaturized wall imaging system specifically for pipeline robots. Our approach involves careful component selection, optimization of the optical system, and integration using 3D printing, resulting in a compact system measuring 25 mm×30 mm×12 mm and offering an optimal lateral resolution of 15.63 μm. Furthermore, we constructed a miniaturized pipeline robot using this system, demonstrating its effectiveness in imaging and quantification. This innovative system can be integrated into various pipeline robots, thereby enhancing their capabilities in capturing detailed information about pipeline walls.