Commercially pure aluminum (1060 Al alloy) was subject to a novel process named Equal channel angular expansion extrusion with spherical cavity (ECAEE-SC) for 1 pass at room temperature. The microstructure development of pure aluminum during processing was investigated using optical microscopy (OM) and electron backscattered diffractometry (EBSD). In addition, the microhardness measurements and tensile tests were conducted for mechanical testing. The results show that the ECAEE-SC process is capable of combined severe plastic deformation and shows high extrusion efficiency, the billet has successfully achieved continuous deformation in a single pass. After 1 pass of ECAEE-SC process, the grains were significantly broken and refined under the combined action of mechanical shear, strain accumulation and hydrostatic pressure. A large number of fine homogeneous equiaxed subgrains were formed. The average grain size was 4.6 μm. Also, the extruded materials showed excellent comprehensive mechanical properties. The microhardness was increased from 36.6 HV to 70.2 HV with uniform distribution, more than 91.8% improvement over the as-cast condition. The tensile strength was up to 183.8 MPa, while the elongation decreased to 12.7%. The tensile fracture morphology exhibited remarkable ductile fracture characteristics.