AbstractA multiple principal elements CuAl10Fe5Ni5Mn1.2 alloy is widely used in the bearing bracket of high speed railway, nuclear power and marine engineering. In traditional metal materials, the evolution of strength and elongation are mutually inconsistent. The multiple principal elements CuAl10Fe5Ni5Mn1.2(wt%) alloy shows the simultaneous improvement of strength and toughness. The present work has systematically studied the strengthening and plasticity behaviors of CuAl10Fe5Ni5Mn1.2(wt%) alloy under complex stirring. The mechanisms responsible for both increasing its strength and plasticity were clarified. It is found that the properties of novel Al10Fe5Ni5Mn1.2 (wt%) alloy are better than other aluminum bronze alloys. Its Rm is 729 MPa, A5.65 is 16% and yield strength (Rp0.2) is 382 MPa. K phases with nano structures distribute in the grains boundaries complete boundaries strengthening. Schmid factor for the basal slip system is from 0.3 to 0.5, which could largely contribute to grain boundary migration and grain rotation. Twinning deformation is initiated and it can open the low angle grain boundaries (LAGBs) and media angle grain boundaries (MAGBs), so the proper combination of strain hardening and plastic deformation enables CuAl10Fe5Ni5Mn1.2 wt% to undergo uniform deformation with micro-nano structures, result in increasing the toughness. The solid solution forms atom scale strengthening. Nano-structures and micron K phase form nano-micro scale strengthening, respectively. Multi-scales strengthening and twinning deformation opening the LAGBs and MAGBs, resulting in increasing both strength and plasticity on the novel CuAl10Fe5Ni5Mn1.2 wt% alloy.