<p>In transpiration cooling, when the coolant flows through a porous matrix, the gradient pressure distribution formed by the mainstream will induce transverse flow of the coolant within the porous medium. In this study, porous materials with randomly distributed pores were constructed to investigate the flow and heat transfer process of a coolant inside the porous medium under a gradient pressure distribution at the outlet. The cooling performance was improved through microscopic pore regulation. The results show that under full penetration conditions, the high-temperature mainstream counter-permeates into the porous medium, leading to significant localized high-temperature effects. By implementing local microscopic pore regulation, the large-area counter-permeation of the high-temperature mainstream into the porous medium can be avoided, achieving flow field reconstruction within the porous medium and enhancing the effectiveness of transpiration cooling.</p>