Given the challenges posed by corrosion in insulated pipes, it is imperative to adopt an effective method for online monitoring. To achieve monitoring of the residual wall thickness of these pipes, a wireless network-based monitoring system utilizing GSDT (γ-ray Digital Scanning Detection Technology) has been developed. This system was tested on insulated pipes, and parallel on-site corrosion monitoring was conducted. Experimental results indicate that the GSDT monitoring system can estimate the residual wall thickness of insulated pipes with a ± 0.0636 mm accuracy at a 95% confidence level. Furthermore, the system’s measurement of pipe wall thickness is not influenced by high-density media, ensuring accurate and reliable measurements. The GSDT monitoring technology aligns with the actual corrosion rate observed on site, indicating its reliability and validity for corrosion monitoring of insulated pipes. Future research should explore the integration of this technology with additional monitoring methods to enhance accuracy and provide comprehensive insights into corrosion behavior.