Abstract: We point out two problems on the existing waveform inversion methods of GPR data in stratified media. They are the problem-solving methods with high time-complexity and the error analysis function with poor convergence. To solve these problems，we propose a novel waveform inversion method with first reaching time restrictions. The proposed waveform inversion method uses the first reaching time of echo signals located in the interface of adjacent medium as a priori information. It can effectively ensure the convergence and speed up the calculation. The experimental results show that the proposed waveform inversion method can identify the geoelectric structure thickness and permittivity parameters，which can be applied on the stratified media reconstruction of GPR data. Besides，it has advantages of low time complexity and inversion results with high precision.