The manipulation of aqueous droplets shows significant promise in drug delivery, cell analysis, and microreactors. In recent years, manipulation techniques based on the photovoltaic effect of lithium niobate have attracted considerable attention. However, owing to the interfacial effect of the solid insulating layer on the lithium niobate surface and the consequent attenuation of the photovoltaic electric field, the manipulation of aqueous droplets has been mostly confined to two-dimensional (2D) planes, which makes it difficult to achieve flexible manipulation in three-dimensional (3D) space. In this work, we propose a photovoltaic manipulation method for aqueous droplets in 3D space. The 3D space, formed by a lithium niobate crystal and a glass substrate, is filled with paraffin oil containing a nonionic surfactant (Span 80) as the surrounding medium for droplet manipulation. In the oil phase, Span 80 molecules self-assemble at the two-phase interface to form an ultrathin molecular layer, which not only effectively suppresses photovoltaic charge transfer, but also significantly reduces resistance to droplet motion. By leveraging the dielectrophoretic force induced by the non-uniform photovoltaic electric field generated upon laser illumination of the lithium niobate, we achieve photovoltaic trapping, levitation, and transport of aqueous droplets in 3D space. Through analysis of the 3D trapping processes for aqueous droplets at different laser powers and Span 80 concentrations, it is found that the 3D trapping height can be precisely and bidirectionally regulated by these parameters, and is proportional to the laser power while inversely proportional to the Span 80 concentration. According to these experimental results and the simulated dielectrophoretic force magnitudes acting on the droplets at different trapping heights, we propose that the increase in 3D trapping height originates from the fact that the dielectrophoretic force increases with the photovoltaic electric field intensity, whereas an increase in Span 80 concentration attenuates the photovoltaic electric field, thus decreasing the trapping height. Furthermore, we also investigate the photovoltaic transport of aqueous droplets in 3D space and reveal the tunable range of the droplet transport velocity and its governing rules. By employing the Span 80 molecular layer as a hydrophobic insulating layer, we successfully extend the photovoltaic manipulation of aqueous droplets from 2D planes to 3D space. The proposed method offers the advantages of contactless manipulation, programmability, and high precision, and provides novel technical solutions and design concepts for 3D optofluidic chips, contactless microreactors, and soft matter manipulation.