The technology of laser deposited repair was used to repair TA15 alloy forgings,and the fracture toughness of substrate,shaped component,body-repaired sample and surface-repaired sample were investigated. Microstructure, fracture surface and longitudinal section morphology of sample were examined by OM and SEM.The results show that the substrate presents duplex microstructure, the repaired zone presents basket weave, and the heat-affected zone shows continuous microstructure transition from duplex microstructure to basket weave.The fracture toughness of shaped component,body-repaired sample and surface-repaired sample are lower than that of substrate, which are 76.4%, 81.0% and 83.1% of substrate respectively.The fracture toughness increases with the increase of the yield difference. When the increase of the yield difference is the same, the fracture toughness of repaired samples increases more significantly than that of substrate, and the increase of the shaped component is the most significant.The cracks expand in a straight line inside the cluste. When the α lamellar cluster with different orientations is encountered, the crack deflects and propagates along the boundary of α lamellar cluster. The smaller the cluster size is, the more serious the deflection is.