After adjusting the camshaft of the automobile engine to the correct timing position, it is fastened to the pulley using bolts. The traditional assembly method has critical drawbacks, including a low level of automation, prolonged cycle times, and excessive pulley wear. Therefore, a sophisticated intelligent automatic assembly system centered around a PLC has been developed. This system integrates advanced functional modules, such as displacement measurement, servo drive, vision detection, and precise tightening. The technology utilizes high-precision sensors to measure and compensate for deviations in engine height in real time, employing advanced vision algorithms based on deep learning to accurately assess the angle of component deviation and automatically align the parts. As confirmed by actual workshop applications, the system has resulted in significant improvements in assembly quality and efficiency, providing essential technical support and valuable practical examples for the intelligent assembly of automotive powertrains and strongly advancing the development of engine manufacturing technology toward intelligence.