To address premature wear of cutter teeth and cutterheads in high-strength concealed shale formations, this study employs a non-contact advance detection method using inductive coil technology. An electromagnetic finite element model simulating roadway-anomaly interactions was developed to systematically analyze how anomaly size, position, and detection depth affect receiving coil sensitivity. Simulations reveal that phase difference exhibits superior sensitivity to conductivity variations: for anomalies >0.1 m radius, it achieves a relative change rate of 810.2% with sensitivity of 9.77 × 10−3∘S−1m, significantly outperforming amplitude ratio (merely 0.116% change rate at >0.4 m radius). Both parameters peak in sensitivity when anomalies are located at the midpoint between transmitter and first receiver coils. For detection depth, amplitude ratio identifies anomalies within 1.5 m (sensitivity 0.001S−1m at 0.5 m), while phase difference shows higher sensitivity within 1 m (0.065∘S−1m at 0.5 m) but faster attenuation due to skin effect. This demonstrates phase difference’s advantage for high-precision shallow small-target detection versus amplitude ratio’s deep-layer capability, with their synergistic optimization at the midpoint providing a theoretical basis for early warning of concealed geological hazards in mining.