Abstract: H13 steel blocks were deposited by cold metal transfer wire arc additive manufacturing （five layers and fifteen passes）. During deposition, subsrate circulating water cooling （at 0 ℃ and 25 ℃）, and follow-up liquid argon spray cooling were applied separately. The effect of fast cooling on the microstructure and properties of the H13 steel was investigated. The results show that under natural cooling （without auxiliary cooling process）, the deposited blocks had coarse grains and high content of martensite-austenite （M-A） islands. By water cooling （both 25 ℃ and 0 ℃） or liquid argon cooling, the cooling rate increased, grain refinement occurred, the number of M-A islands decreased, and the difference in M-A island content between the main area and the overlapping area reduced. The hardness of the H13 steel cross-section was the highest under liquid argon cooling, followed by 0 ℃ water cooling, with natural cooling yielding the lowest values. With increasing the cooling rate （natural cooling to 25 ℃ water cooling and then to 0 ℃ water cooling）, the tensile strength, and elongation after fracture of the H13 steel increased, while the difference in tensile strength between the main area and the overlapping area decreased. Compared with the main area, the overlapping area of H13 steel blocks consistently showed a coarser microstructure, a higher number of M-A islands, lower hardness and tensile strength, and a slightly higher elongation after fracture. Improving cooling rate could decrease the difference of microstrueture and properties in differernt region.