Abstract: Faults are critical geological factors that constrain the survey, design, and construction of deep-buried tunnel engineering. Accurately obtaining the spatial distribution and development characteristics of faults is of great significance for ensuring engineering stability and optimizing route alignment. To address the challenge of fine-scale fault detection in steeply dipping metasedimentary rock areas under conditions of complex topography, strong electromagnetic interference, and deep burial, this paper proposes a combined microtremor and seismic refraction tomography technique that enables both deep fault reconnaissance and shallow fine-scale localization. First, the large-depth microtremor method is employed for rapid reconnaissance of velocity anomalies associated with faults. Second, the microtremor results are used to constrain the forward modeling of refraction tomography, thereby optimizing the observation system. Finally, refraction tomography is combined with forward modeling experiments simulating faults of varying widths to locate and analyze the faults. The results demonstrate that the combined method can clearly identify faults and provide key information on spatial location, dip direction, and developmental scale, which are in good agreement with drilling data. This study offers a feasible technical approach and engineering reference for the precise positioning and semi-quantitative analysis of steeply dipping faults in deep-buried tunnel engineering.