The microtremor H/V spectral ratio method, which studies site response by calculating the amplitude spectral ratio of the horizontal and vertical components of microtremor signals, has been widely applied in the field of engineering seismology. To investigate the inversion methods for the microtremor H/V curve, the forward analysis of the microtremor H/V spectral ratio curve was carried out using the diffuse field method. This process explored the influence of various subsurface parameters on the microtremor H/V curve and validated the effectiveness of the inversion method through case studies. The forward analysis results indicated that layer thickness and shear wave velocity significantly affected the shape and peak frequency of the microtremor H/V curve, while changes in compressional wave velocity and medium density had negligible effects on the peak frequency and amplitude. Therefore, layer thickness and shear wave velocity should be primarily considered during inversion. The inversion results of three typical subsurface models showed that the model with increasing velocity layers had smaller inversion errors, while the models with high-velocity hard interlayers and low-velocity soft interlayers had relatively larger errors. Microtremor data were collected, and the measured H/V curve was calculated. The inversion results of the measured H/V curve are consistent with the drilling data and can effectively identify the depth of the bedrock surface. Thus, the microtremor H/V spectral ratio method can effectively invert the subsurface wave velocity structure.