Due to the negative resistance characteristics of power electronic devices, high-penetration renewable energy power systems face significant resonance stability issues. Limited by heavy high-order determinant computations, the conventional s-domain node admittance matrix method becomes inefficient for large systems. To address this problem, the s-domain node admittance matrix method is optimized by impedance aggregation, enabling fast resonance stability analysis for high-penetration renewable energy power systems. Firstly, the s-domain impedance models of typical components in high-penetration renewable energy power systems are presented, together with the procedures of the conventional s-domain node admittance matrix method. Next, a general impedance aggregation method independent of system topology and scale is proposed. The partial inheritance of resonance modes and node voltage mode shapes in impedance-aggregated systems is revealed, and regional observability and regional linkage are introduced to distinguish global modes and local modes. Then, node numbering rules and analysis procedures for the optimized method are developed, transforming the resonance stability analysis for the complete system into a collection of subsystem analyses, and the efficiency improvement is verified in terms of asymptotic computational complexity. Finally, resonance stability analysis is conducted on an offshore wind power system in Zhejiang Province, validating the effectiveness of the proposed method.