Abstract: With the increasing demand for efficient and intelligent production in the modern machinery manufacturing industry, traditional methods of processing planer knives suffer from low efficiency and inconsistent precision, failing to meet industry requirements. To address this issue, this paper designs an automated production line for planer knife processing based on PLC control. The production line adopts the Siemens S7-200 SMART PLC as the core control unit, integrating robotic loading/unloading, CNC machine tool processing, a flipping station, and fixtures to achieve fully automated processing of planer knives, including operations such as facing, grinding assembly surfaces, and precision grinding of inner and outer circles. The U-shaped layout of the production line, along with the coordinated operation of robots and CNC machine tools, significantly improves production efficiency and machining accuracy. Experimental results demonstrate that the system increases production efficiency by over 30% while maintaining machining precision errors within ±0.01 mm. Additionally, the system incorporates configuration software to enable real-time monitoring, online alarm functions, and intelligent statistical analysis, effectively reducing defect rates and enhancing production stability and reliability.