Abstract: In order to explain the influence mechanism of the cold island effect in urban parks to alleviate the heat wave under different landscape characteristics, this study explored the response changes of 24 urban parks in Dalian to heat wave environment based on land surface temperature data retrieved by Landsat 8 thermal infrared band. The result showed that heat wave had a significant impact on the land surface temperature. Under the heat wave environment, the change in cooling range (ΔC) of parks ranged from −68.38 to 92.67 m, and the change in cold island intensity (ΔP) ranged from −1.532 to 0.783°C. Different parks had different responses to heat waves. And the changing trends of ΔC and ΔP in the same park were not completely consistent. The important landscape parameters affecting ΔC were forest area ratio, grassland area ratio, and grassland aggregation degree. The important landscape parameters affecting ΔP were surface area ratio, water area ratio, and grassland area ratio. When dealing with the heat wave environment, the urban parks with the resistance type (ΔC>0 and ΔP>0) can better mitigate heat waves, and the forest area ratio was usually more than 48.5%, land surface area ratio was less than 11%, water area ratio was greater than 29%, grassland area ratio was less than 41%, and grassland aggregation degree was less than 97.8%.