γ-Ni toughened Mo2Ni3Si ternary metal silicide alloy was designed and fabricated by the laser melting deposition process. Differential scanning calorimetry (DSC) and high-temperature microscopic analysis indicated that the Mo2Ni3Si alloy has an eutectic temperature of 1287 ℃ and a liquidus temperature of 1355 ℃. In this paper, the solidification microstructures of γ/Mo2Ni3Si alloy under furnace cooling, water cooling and laser surface remelting conditions were studied. Results showed that under furnace cooling and water cooling conditions, the volume fraction of Mo2Ni3Si primary dendrite and the secondary dendrite arm spacing decreased with increasing cooling rate. However, for the alloy under laser surface remelting condition which had the highest cooling rate (～103 K/s), the volume fraction of Mo2Ni3Si primary dendrite increased markedly to about 62%. Due to its finest structure, the laser surface remelted γ/Mo2Ni3Si alloy possessed the optimum mechanical property (600HV), while many microcracks were observed on the Mo2Ni3Si primary dendrite for the furnace cooled γ/Mo2Ni3Si alloy and its coarse dual-phase structure was much unfavourable to mechanical property.