At present, low permeability resources are the focus of the development of petroleum industry. In this paper, firstly, the oil displacement mechanism under the condition of vertical and horizontal well combination is clarified. Secondly, the difference of the mechanism of enhancing oil recovery between asynchronous and inter-fracture injection and production is revealed. Thirdly, the difference of energy supplement mechanism between huff and puff and displacement is compared and analyzed. Results show that: (a) with asynchronous injection-production development, the oil saturation drop around the water injection well is greater than that of periodic injection-production and synchronous injection-production. (b) Under the dual effects of water injection pressure difference and capillary force, part of the injected water enters the reservoir with relatively small pore channels, expanding the swept volume. (c) In the soak stage of asynchronous injection-production development, capillary force is the main control factor of oil-water permeability, and its size determines the permeability level. (d) The injected water first flows through the large channel and then flows into small channel to complete the imbibition and replacement. (e) The flow field of asynchronous injection-production has a large sweep range, which is conducive to improving oil recovery.