Real time and stability are crucial requirements in transmission line inspection. Software can quickly process image data and output results while maintaining stability to cope with various complex environments and operating conditions, which is highly challenging. Therefore, this article designs a new X-ray digital imaging software for transmission line inspection robots. The imaging system for robot X-ray defect detection software is composed of a BJI-1X light generator and a Raines digital imager. According to this imaging principle, internal image information of defects is collected using X-ray digital imaging instruments, and defect categories are obtained using image processing software based on its hierarchical recognition model. Using Faster RCNN algorithm to construct defect area localization model, improve digital imaging accuracy, and ultimately output digital imaging results. The experimental results show that when the balance factor is set to 0.30 and the adjustment factor is set to 1.5, the software in this paper has the highest accuracy in digital imaging of defects. The software in this article can accurately locate the defect area, obtain its location boundary box, and has high clarity. It also has excellent digital imaging performance in determining the type of digital imaging defect.