Deep-sea hydraulic system has a high demand for the quality of hydraulic oil. Vacuum filtration and heating operation can effectively remove the water and air bubbles in the mixed oil. A multifunctional oil equipment is proposed in this paper, which possesses both oil filtering and filling functions by vacuum-heating filtering and vacuum-high pressure oiling methods. Finally, the purification effect of the equipment was tested and the experimental data proved the good purification performance of this multifunctional oiling equipment.