<p>Soil liquefaction remains a significant threat to infrastructure built on saturated silty deposits. To evaluate its key influencing factors, this study investigates the effects of clay content (CC), fines content (FC) and intergranular void ratio (<i>e</i>_<i>i</i>) on the liquefaction resistance of saturated silty soil. A series of undrained cyclic triaxial tests were conducted on reconstituted specimens with varying CC and FC. The results indicate that the cyclic resistance ratio (CRR) does not correlate well with fines or clay content alone. To quantitatively assess liquefaction resistance, the concept of the intergranular void ratio of silty soil is introduced, which better reflects the active soil skeleton state from a microstructural perspective by considering particle contact mechanisms. Analysis of the experimental data reveals a negative power-law relationship between <i>e</i>_<i>i</i> and CRR. For specimens with CC ≤ 8%, this relationship is quantified as CRR = 0.362·<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\:{e}_{i}^{-0.771}\)</EquationSource> </InlineEquation>with R² = 0.94. This study establishes <i>e</i>_<i>i</i> as a superior state parameter and provides a new perspective on evaluating the liquefaction potential of silty soil by linking microstructural parameters to macro-scale behavior.</p>