Abstract: In order to improve the power cycle performance, a printed circuit heat exchanger (PCHE) is applied to the intercooled recuperated gas turbine. The flow and heat transfer performance of variable physical properties of flue gas and water in the airfoil channel of the printed circuit heat exchanger is numerically studied. Based on the first and second laws of thermodynamics, the influence of the lateral and longitudinal pitches of fins on the flow and heat transfer performance is analyzed. The influence weights of various factors are analyzed by orthogonal experiments, and the heat transfer and flow correlations are proposed. The results show that the comprehensive performance of the printed circuit heat exchanger increases with the increase of the longitudinal pitch under the two working fluids. When the working fluid is water, the comprehensive performance of the heat exchanger increases with the decrease of the lateral pitch. The comprehensive performance of the heat exchanger with the lateral pitch of 2.4~3.6mm is best for the flue gas. The heat transfer enhancement is closely related to the synergistic effect between the velocity and temperature gradient. Different longitudinal and lateral pitches could affect the development of the boundary layer, thereby affecting the flow and heat transfer performance of the heat exchanger. Increasing the lateral and longitudinal pitches could effectively reduce the irreversible loss in the heat transfer process. The present work could provide guidance for the optimal design of airfoil printed circuit board heat exchanger in gas turbine cycle.