Usually, monolithic bulk metallic glasses undergo inhomogeneous plastic deformation and exhibit poor ductility (<2%) at room temperature. We report a newly developed Pd–Si binary bulk metallic glass, which exhibits a uniform plastic deformation and a large plastic engineering strain of 82% and a plastic true strain of 170%, together with initial strain hardening, slight strain softening and final strain hardening characteristics. The uniform shear deformation and the ultrahigh plasticity are mainly attributed to strain hardening, which results from the nanoscale inhomogeneity due to liquid phase separation. The formed nanoscale inhomogeneity will hinder, deflect, and bifurcate the propagation of shear bands.