A novel branch-trunk Ag hierarchical nanostructure was synthesized by hydrothermal synthesis combined with microwave-assisted synthesis with Te nanowire as template. The Te nanowire was synthesized via hydrothermal process. The branch-truck Ag hierarchical nanostructures were constructed on Te nanowires through via galvanic replacement reaction with Te nanowire as the sacrifice temple with microwave-assisted synthesis method. We further investigated the potential application of the obtained hierarchical nanostructures for ascorbic acid electrochemical sensor analysis. The results showed the as-prepared sensor exhibited a wide liner range with 0.17 μM to 1.80 mM (R = 0.999) and the detection limit was estimated to be 0.06 μM (S/N = 3). These results indicated the branch-truck Ag hierarchical nanostructures were an excellent candidate material for sensing application.