Smart factories integrate multiple advanced technologies to realize an efficient production line. Advanced technology is used to improve the manufacturing and production process including the technology of 5G, virtual reality, machine learning, augmented reality, and data analytics. These have been pushing manufacturing plants into smart manufacturing. The main goal of this research is to provide a non-intrusive intelligent smart sensor system and 5G edge computing gateway for the smart factory. The industrial IoT of data acquisition and processing is realized through nonintrusive intelligent sensors and a 5G edge computing gateway for the identification of mechanical faults and equipment health status on the manufacturing production line. The non-intrusive smart sensor system for data transmitters developed in this research does not require an external power supply and uses the data exchange through wireless communication architecture to collect data based on the power network and machine vibration and temperature. By using the intelligent smart sensor system to predict equipment health status for maintenance needs, the intelligent smart sensor system reduces the time and human resources for monitoring the equipment of the industrial control system. The predictive maintenance application uses timedomain signal features for fault diagnosis. It is estimated correctness of fault morphology diagnosis is 90 % and the maintenance cost can reach 15-40% of the production cost.