Abstract: In application scenarios, there often exists thin coverings on the surface of the ground penetrating radar medium, which will affect detection effect, we propose a layered medium parameter inversion method based on the reflection signal reconstruction. The novelty of our method is that it solves the problem that the thickness of the cover layer is usually less than the minimum resolvable thickness of the ground penetrating radar. In this process, we first use the generalized reflection coefficient to establish a time-domain model of radar emission echo; Then optimize the cost function of the model through genetic algorithm to inverse the parameters of the thin layer of the cover; Finally, we use gprMax simulation software simulates the paving scene of asphalt concrete, which verifies and analyzes the effectiveness and accuracy of the proposed algorithm.