Experimental studies are performed to investigate the cooling performance for the typical jet array impingement/film cooling configurations within the multi-layer turbine casing. Regarding to the non-uniform impingements, the effects of jet crossflow and film cooling on heat transfer coefficients on the target plate are studied, i.e. the jet Reynolds numbers (6 750—28 500) and the outflow to crossflow ratios (0—0.5). It is found that the local and area-averaged Nusselt numbers are enhanced as the impingement Reynolds number increases. While they decrease gradually with a larger outflow to crossflow ratio. The results indicate that higher local Nusselt number will be obtained with a smaller distance between the film hole and the jet hole. The enhanced heat transfer induced by impingement is weakened due to the extraction of crossflow. This phenomenon becomes to be more distinguished when the outflow to crossflow ratio increases. 