Objective To investigate the interaction between von Willebrand factor (VWF) A1 and A3 domain, and type 2M mutant W1745C-A3 effect on the thermal stability and mechanical stability of A1/A3. Methods The crystal structures of A1 and A3 were downloaded from Protein Data Base (PDB). Using SwarmDock Server to obtain wild-type (WT) A3/A1 structure, then W1745C-A3/A1 mutant was constructed by replacing the Trp1745 with Cys1745 in WT-A3/A1. Through Steered molecular dynamics simulation, the formation and evolution of hydrogen bond and salt bridge between A1 and A2 interfaces were observed, and the differences on conformation, disrupted force and dissociation time between WT-A1/A3 and W1745C-A3/A1 were be analyzed and compared. Results There were 5 pairs of hydrogen bonds with survival rate > 0.2 and 1 pair salt bridge with survival rate > 0.5 between A1 and A2. The W1745C-A3/A1 complex could withstand greater disrupted force and longer dissociation time compared with WT-A3/A1, by improving the stability of hydrogen bonds and increasing 1 pair stable salt bridge. Conclusions The interaction between A1 and A3 would hinder the binding sites of A1 to GPIbα, and the W1745C-A3 mutation would further reduce the affinity of A1 to platelets. These results would be helpful for revealing the molecular mechanism of von Willbrand disease and developing the corresponding drugs targeted to hemostasis disorders.