The laser deposition repair technology is used to repair the tensile specimen with pre-damage and the microstructure, tensile fracture and its neighboring deformation structure are examined and analyzed by the optical microscope and scanning electric microscope. The results show that the microstructure at repaired zone is composed of Al dendrites and Al-Si eutectic whose Si-phase presents Coral-like morphology. The tensile strengths at room temperature of specimens with repair-ratios of 10% and 20% can reach up to 90% and 88% of the casting standard and their elongation rates are both superior to the casting standard; the fracture mechanism at substrate zone is brittle-fracture type, while that at repair zone is ductile-fracture type; the fracture mode for micro-fractures at substrate zone is transgranular, while that at repair zone is granular.