Numerical simulation was carried out to study the heat transfer characteristics of the double-wall structures with pin-finarray. The Nusselt number distributions and the averaged values on the target surface, impingement surface and pin-fin surfaces at the different locations were analyzed at impingement Reynolds number ranging from 1.0 × 10⁴ to 6.0 × 10⁴. The second peak of the Nusselt number distribution appears on the target surface, where the Nusselt number is greater than that on the stagnation point. The maximum spanwise averaged Nusselt numbers on the impingement surface were found at the positions of the second row and the fourth row of pin-fins next to the impingement holes. The heat transfer characteristics on the pin-fins at different rows are different. The Nusselt number on the pin-pin in the same row to the impingement hole is the largest, showing the heat transfer characteristics of the fountain flow. The Nusselt number on the second row and the fourth row of the pin-fins are second, showing the heat transfer characteristics of rolling flow around pin-fin. The Nusselt number of the first row and the fifth row of pin-fins far away from the impingement hole are the smallest, showing the heat transfer characteristic of flow across pin-fin. With the Reynolds number varying from 1.0 × 10⁴ to 6.0 × 10⁴, the surface averaged Nusselt numbers of the third pin-fin row, the second and the fourth, and the first and the fifth row increase by 306%, 325% and 360%, respectively.