Abstract: Large size A356 aluminum alloy tube blank was prepared by multilayer spray deposition technology, and the microstructure characteristic and the effect of subsequent rolling and heat treatment on microstructure and mechanical properties were analyzed by using optical microscopy, SEM, X-ray diffractometer and tensile tester. The results show that the microstructure of A356 aluminum alloy tube blank prepared by spray deposition was tiny but contained a little pores, and the secondary phase was subsphaeroidal eutectic silicon and short-rod-like iron-rich phase. The spray deposition blank was preformed via large quantity of atomized droplets bonding. The pores in deposition blank and the weak boundary strength between original powders could be eliminated by proper rolling and heat treatment, and the mechanical properties were raised.