Abstract: Objective: The choice of different detection parameters (borehole spacing, receiver spacing, source spacing) in seismic wave CT (computer\|aided tomography) technology has a direct impact on the accuracy of detecting underground boulders in subway engineering. It is important to select the detection parameters reasonably. Method: The basic principle of seismic wave CT technology is explained. Taking an actual engineering example of a station on Fuzhou Metro Line 1, the seismic wave CT detection is conducted using three different bore\|hole spacing (4.6 m, 10.4 m, and 15.0 m) under the same detection conditions, and the detection results are compared and analyzed. Based on this, under two different bore\|hole spacing conditions (14.5 m and 10.5 m), four combinations of receiver spacing are selected and compared to analyze the detection results. Result &Conclusion: The use of smaller bore\|hole spacing (4.6 m and 10.4 m) can reflect the distribution pattern and specific locations of isolated rocks more accurately. When using larger bore\|hole spacing (15.0 m), the detected distribution range of isolated rocks is larger than the actual distribution, and the morphological characteristics are more blurred. Compared to larger source and receiver spacing values (both 2.0 m), smaller values (both 0.5 m or 1.0 m) provide higher detection resolution for isolated rocks. The reasonable parameter values for seismic wave CT are: 10.0 m for bore\|hole spacing, 1.0 m for source spacing and receiver spacing both.