Accurate and real-time microseismic event localization is essential for monitoring subsurface engineering activities, but migration-based workflows rely on densely sampled three-dimensional traveltime tables whose storage and disk-I/O demands increase rapidly with model size and receiver coverage. For migration-based microseismic localization using three-dimensional traveltime tables, we introduce error-bounded (absolute [ABS]/relative [REL]) lossy compression via SZ2 and assess engineering viability with a full tolerance sweep and a continuous-location evaluation. On a synthetic dataset (170 × 170 × 170 grid, 8 channels), ABS bounds of 0.4–1 ms yield compression ratios of ≈13.8–16.2× with location error d_loc ≈ 0.2–0.8 m and origin-time bias |∆t₀| ≤ 0.05 ms. In a 30-event joint test at ABS = 1 ms, the median d_loc is 2.03 m (P₉₅ = 7.76 m) and P₉₅ (|∆t₀|) < 1 ms. A field-scale case (16 × 16 × 3.72 km; raw 479.92 MB) shows that equivalent absolute errors A_eq ≈ 0.1–2.6 ms achieve ≈ 6.3–15.8× volume reduction; under tight bounds, error slices are smooth and structure-conforming (e.g., P₉₉ < 0.26 ms), and ABS = 1 ms reaches 13.61×. Comparing schemes at the same A_eq, REL often attains higher ratios but amplifies localization bias earlier in near-source, small-traveltime regions; ABS provides geometry-agnostic, uniform error control with greater localization robustness. We therefore recommend ABS ≈ 0.4–1 ms for real-time localization, whereas REL with A_eq ≈ 0.3–2.6 ms is suitable for archiving and fast loading. Realistic examples demonstrate the effectiveness of the optimized traveltime table storage strategy.