There are many precious cultural relics of paintings and calligraphy in museums of China, but effective restoration of them is difficult due to their material characteristics. Paste between paintings or calligraphy and backing papers is the main obstacle in the process of taking off old backings. Amylase has been used to effectively decompose starch paste, which improves the efficiency of taking off old backings; however, residues of amylase on cultural relics could influence subsequent remounting. Therefore, development of a thermosensitive amylase could contribute to the process of remounting after taking off old backings. In our study, a bacterial strain named BWL1025 that can secrete thermosensitive amylase, was isolated from soil sampled in the cold northeast area. Using methods of molecular biology, the strain BWL1025 was identified as Bacillus subtilis. The optimum conditions for enzyme activity, the pH stability, the lowest inactivation temperature and the minimum inactivation time of the amylase produced from BWL1025 were determined by the DNS method. The results show that the enzyme activity reached its highest activity of 0.839 IU/mL at 40 ℃, but almost disappeared after 25 minutes at 60 ℃. In addition, we optimized the fermentation conditions of the strain BWL1025, and found that the highest activity of 1.63 IU/mL was observed when yeast extract was used as nitrogen source and xylose as carbon source. This study provides a good enzyme source for taking off old backings from cultural relics of paintings and calligraphy.