为探究卸荷槽结构对外啮合齿轮滑油泵空化噪声的影响规律，在不同转速条件下，采用Pumplinx软件结合RNG k-ε湍流模型与全空化模型进行瞬态流场仿真，并基于Lighthill声类比理论进行流致噪声耦合分析，系统探究卸荷槽结构对泵内流量脉动、空化发展及噪声辐射特性的作用机制。结果表明：卸荷槽可降低流量脉动幅值，并使空化体积减少约20%；噪声能量集中于基频及其倍频，且随转速升高辐射增强；配置卸荷槽后噪声声压级较无槽结构降低5–10 dB，其中圆形卸荷槽表现出较好的噪声控制性能，为卸荷槽的形态优化提供了方向。

To investigate the influence of relief groove structures on cavitation noise in external gear lubricating pumps under different rotational speeds, transient flow field simulations are conducted using Pumplinx software coupled with RNG k-ε turbulence model and full cavitation model. Subsequently, the analysis of flow-induced noise is performed based on Lighthill’s acoustic analogy theory. This work systematically examines the effects of the presence or absence of relief grooves on flow pulsation, cavitation development, and noise radiation characteristics within the pump. Results indicate that relief grooves decrease the flow pulsation amplitude and reduce the cavitation volume by approximately 20%. Noise energy is predominantly concentrated at the fundamental frequency and its harmonics, with elevated rotational speeds leading to enhanced noise radiation. Compared to configurations without relief grooves, those equipped with relief grooves achieve a 5–10 dB reduction in sound pressure level, among which circular relief grooves exhibit superior noise control performance, providing a direction for the morphological optimization of relief grooves.