Amylosucrase (AS) is a kind of glucosyltransferase (E.C. 2.4.1.4) belonging to the glycoside hydrolase (GH) family 13. In the presence of an activator polymer, in vitro, AS is able to catalyze the synthesis of an amylose-like polysaccharide composed of only α-1,4-linkages using sucrose as the only energy source. Unlike AS, other enzymes responsible for the synthesis of such amylose-like polymers require the addition of expensive nucleotide-activated sugars. These properties make AS an interesting enzyme for industrial applications. In spite of the great application potential, industrial applications of AS were largely hampered by its low stability. In this work, the structure of Arthrobacter chlorophenolicus amylosucrase (AcAS) was modeled according to crystal structures of Neisseria polysaccharea amylosucrase (NpAS) and Deinococcus geothermalis amylosucrase (DgAS). The structural difference of the three AS were investigated for the sake of exploring the working mechanism of AcAS. The dynamics and functional motions of AcAS were also investigated by the Gaussian network model (GNM). Based on GNM, it was found that AcAS can be divided into two regions with different moving directions. Finally, the unfolding property of AcAS was studied by the iterative GNM, and several kinetically weak regions were identified on the basis of the predicted unfolding pathway. These discoveries may be helpful to the industrial development of AS.