At the beginning of 1970s, conservators at National Museum of China started research on the protection and restoration of ironware. According to the degree of rust, the cultural relics protection and restoration personnel carried out cleaning, rust removal, desalination, bonding and sealing treatments. When examining and reviewing the four iron wares that were protected and restored at that time for fully understanding the previous restorations done on these iron wares, the work uses Fourier Transform Infrared Spectroscopy (FTIR) and Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC/MS) to analyze the restoration materials used in the collection of ironware. Py-GC/MS does not require sample pretreatment when analyzing samples, and the samples can be directly analyzed by thermal cracking, and the operation is relatively simple. In addition, this method requires a small amount of sample. It can not only provide a scientific evaluation the repair materials in iron wares, but also provide important guidance for evaluating the protection and restoration methods used in the past and the long-term preservation of iron wares.