Fused Deposition Modeling (FDM) 3D printing has emerged as a highly utilized technology worldwide due to its user-friendly operation, ability to work with several materials, and environmentally conscious approach. Nevertheless, the limitations of technological development result in the persistence of weaknesses in FDM 3D printing, such as extended printing duration, irregularities in the electromechanical transmission system, and inconsistent printing quality. The study aims to investigate online condition monitoring methods in the FDM 3D printing process, concentrating especially on the fusion of many information sources. Prior to this, the optimal placement of the fixed sensors has been deliberated. Subsequently, an examination was conducted on the attributes of the printing route and the optimal conditions of the synchronous transmission belt using multi-information. Furthermore, an analysis was performed on the distinctive qualities of each signal in order to establish a correlation between the signals and the 3D printing procedure. Lastly, the efficacy of each signal will be examined to suggest the need for additional investigation. Current evidence suggests that mounting the sensor on the nozzle module yields higher efficiency compared to alternative mounting sites. Additionally, the vibration frequency and current signals provide clear insights into the printing process and the condition of the synchronous transmission belt.