Here, an MeV proton beam irradiation-induced nano-welding technique to fabricate X-, Y-, II-and T-shapes molecular junctions between silver nanowires using high proton beam current is demonstrated. Transmission electron microscopy, scanning electron microscopy and Xray diffraction revealed that nano-welding of Ag-NWs is successfully achieved with stable crystal structure. Nano-welding process and corresponding large-scale fabrication of networks are discussed.