Porcelain insulators play a crucial role in providing mechanical support and electrical insulation in high-voltage transmission lines. However, porcelain insulators inevitably degrade over long periods of operation, which can lead to serious incidents such as flashovers and insulator string falls. Therefore, researching convenient and reliable methods for insulator detection is of significant importance for the reliability of power systems. This study employs finite element analysis to simulate a 110 kV insulator string model, obtaining results on the voltage distribution of the insulator string when zero-value insulators appear at different positions, and provides a detailed analysis of the impact of zero-value insulators on the voltage of other insulators. The results indicate that insulators at the high-voltage end, low-voltage end, or adjacent to the zero-value insulator are more significantly affected. The findings provide theoretical and data support for detecting degraded insulators. Additionally, this paper proposes an insulator detection strategy that avoids inspecting each insulator individually, thereby significantly reducing the workload.