With the rapid development of the national economy, the adoption of ultra-high voltage (UHV) transmission technology has become a necessity. Dry-type air-core reactors, due to their advantages such as non-saturation, high strength, lightweight, and low noise, are widely used in power systems. As a high proportion of new energy sources are integrated into the power grid, the failure rate of dry-type air-core reactors has gradually increased, with inter-turn short circuits being one of the main faults. Investigating the partial discharge mechanism of dry-type air-core reactors and employing the high-frequency pulse oscillation test method to detect inter-turn short circuit faults is of significant importance for ensuring the safety and reliability of power systems. This paper studies the detection methods for partial discharge and inter-turn short circuit faults in dry-type air-core reactors. Through simulation, the partial discharge mechanism is thoroughly explored, and the effectiveness of the high-frequency oscillation voltage method in practical applications is validated. The results show that this method can effectively identify and eliminate reactors with inter-turn insulation defects, improve the operational reliability of reactors, and prevent severe faults, thereby demonstrating significant practical value.