The interference components of the seismic data collected in the field tunnel seismic forward prospecting are complex with strong energy and mutual overlap, which seriously influences the quality of seismic records. In order to address the problem of tunnel seismic data denoising, the time-frequency domain spectral subtraction method was adopted in this paper to transform the seismic data into the time-frequency domain for processing. The results show that this approach reduces the estimation error of the noise spectrum, effectively removes the noise from the tunnel environment, improves the resolution in the frequency direction, and provides high-quality data for the subsequent offset imaging. Based on the C1 convey tunnel of the Zhujiang Delta Water Resources Allocation Engineering, seismic forward prospecting is carried out. The imaging results are basically consistent with the tunnel excavation result, which fully verifies the effectiveness and practicability of this method.