The focus of this study is to explore the thermodynamic characteristics of an intermediate heat-exchange cycle (IHEC) system in aero engines, employing experimental analysis. Using air, fuel, and intermediate working fluid (IWF) as working mediums, an IHEC system experimental platform incorporated two heat exchangers (HEX) was established. A theoretical analysis model for characteristics of the IHEC system was developed using the heat current method and a novel method for estimating the overall heat transfer coefficient (K). Deviations between experimental and simulation results for system equilibrium heat transfer rates and temperatures at each node of the IHEC system are within ±10%, and the maximum average relative deviation of the proposed method for estimating K is −7.93%. Detailed analyses have been conducted regarding the effects of fuel mass flow rate, IWF mass flow rate, air mass flow rate, and air inlet temperature on the system. Raising the fuel mass flow rate leads to reduced temperatures at each system node, while the system's equilibrium heat transfer rate initially increases and then stabilizes. Variations in IWF mass flow rate have complex impacts on the IHEC system, influenced by HEX design margins and heat transfer capacities. Tailored analyses are necessary based on specific circumstances. •A theoretical analysis model for system-level characteristics of the IHEC system was developed.•A two-stage heat exchanger combined IHEC system experimental platform was established.•Different parameter's effects on systematic thermodynamic performance have been conducted.•The accuracy of the mathematical model was verified by experiments.