Abstract: A monitoring system for in-situ identification of anomalies of a workpiece in a 3D printing manufacturing process is provided. The monitoring system includes an optical sensor having an optical path; an infrared sensor having an IR path; an optical device configured to merge the optical and the IR paths to obtain a merged optical path, which is arranged to be directed to the workpiece during a first stage of a 3D printing manufacturing process to obtain a first perception data; and a processor configured to identify anomalies of the workpiece based on the first perception data. A method is also provided. The method includes steps of: merging an optical path of an optical sensor and an infrared path of an IR sensor using an optical device to obtain a merged path; directing the merged path to the workpiece during a first stage of a 3D printing manufacturing process to obtain a first perception data; and identifying anomalies of the workpiece based on the first perception data.