本文利用2015至2020年TIOON(Tropical Indian Ocean Observation Net)观测潜标在赤道80°E、85°E和93°E的环流时间序列及BRAN2020环流流速数据，研究了印度洋赤道深层环流 (1200米以下) 的季节内变化特征及其驱动机制。观测结果显示，潜标位置的纬向流速范围为0.21 ± 3.05 cm s^-^1至0.29 ± 2.50 cm s^-^1，经向流速范围为−0.03 ± 2.61 cm s^-^1至0.05 ± 3.14 cm s^-^1。纬向流和经向流的季节内周期信号强度分别占各自总流动强度的88%-91%和74%-84%，揭示了深层环流中的显著季节内周期变率特征。小波分析表明，深层纬向流季节内信号主要周期为10−100天，其中80°E处的周期较长(50-90天)，而93°E处的主要为50天及更高频信号，表现为蓝移现象，即环流变化的主导频率随位置靠东而变高的现象。经向流季节内信号以60天周期最显著。赤道风应力异常是深层环流季节内变率的重要驱动因素。中海盆(80°E和85°E)深层环流季节内变率主要受纬向风应力异常驱动，通过反射波动过程调制；基于低阶斜压模态，能量通过Kelvin波在东边界反射后形成的Rossby波向深层传递。东海盆(93°E)深层环流季节内变率主要受纬向和经向风应力异常驱动，通过直接波动过程调制；基于多阶斜压模态，能量通过在环流西侧由风直接驱动产生的Yanai波向深层传递。根据线性波动理论，本研究刻画了上述赤道波的能量传播射线，结果显示地形对赤道波调制深海环流的动力过程有重要影响：中海盆的平坦地形有利于向下向西传播能量的反射波动过程，而90°E附近的海脊可能会阻碍向下向东传播能量的直接波动过程。本研究加深了对深层环流动力学的理解，为改进深海环流模拟提供了观测依据。

The intraseasonal variability of the equatorial deep currents (below 1200 m) in the Indian Ocean are investigated in this paper based on the 2015-2020 deep current velocity timeseries obtained from TIOON (Tropical Indian Ocean Observation Net) mooring at 80°E, 85°E, and 93°E on the equator, along with a continues current velocity from BRAN2022. Observations show the zonal current velocities at three locations range from 0.21 ± 3.05 cm s^-^1 to 0.29 ± 2.50 cm s^-^1, and the meridional current velocities range from -0.03 ± 2.61 cm s^-^1 to 0.05 ± 3.14 cm s^-^1. The intraseasonal variability of the zonal and meridional currents accounts for 88%-91% and 74%-84% of the total current variability, respectively, highlighting the significance of intraseasonal variability. Wavelet analysis indicates that the main period of the intraseasonal deep zonal currents is 10-100 days, with a longer period (50-90 days) at 80°E and a shorter period (< 50 days) at 93°E. This suggests blue-shift phenomenon that the variability of the deep currents shifts to a higher frequencies when being more eastern. The intraseasonal meridional currents exhibits a significant peak at the 60-day period. The equatorial wind stress anomaly is an important forcing to drive the intraseasonal variability in deep currents by direct and reflected wave processes. In the central basin (80°E and 85°E), the intraseasonal variability is primarily driven by the zonal wind stress anomaly and modulated through a reflected wave process. Energy is transferred to the deep layers via Rossby waves that are formed by Kelvin waves reflected at the eastern boundary, predominantly based on low-order baroclinic modes. In the eastern basin (93°E), the intraseasonal variability of deep currents is mainly driven by both zonal and meridional wind stress anomalies and modulated through a direct wave process. Energy is transferred to the deep layers via Yanai waves directly generated west of the current, involving multi-order baroclinic modes. Based on the linear wave theory, this study depicts the energy propagation rays of equatorial beams, showing that topography plays an important role in the dynamics of deep circulation by affecting equatorial beam energy propagation. The flat topography at central basin enables energy propagating downward and westward by reflected wave process, while the ridge near 90°E may obstruct energy propagating downward and eastward by the direct waves process. This study deepens the understanding of deep currents dynamics and offers observational evidence for improving deep ocean circulation simulations.