There are some problems in water drive development of low permeability reservoirs，such as insufficient formation energy and difficult water injection. On the one hand，the water injection pressure is high and the under injection is serious. On the other hand，the formation pressure drop is large，the production capacity decreases rapidly. The oil production rate and recovery degree are low. There are still various forms of residual oil such as film or oil drop after water flooding. Aiming at such problems， the asymmetric Gemini surfactant was prepared from epichlorohydrin，dodecyl dimethyl amine and metronidazole. It was compounded with dehydrogenated rosin surfactant，cetyl alcohol and ethanol to obtain a functional injection increasing oil displacement agent. The emulsifying ability，wettability，anti-swelling，depressurization，injection increase and oil displacement effect of the agent were studied. Then it was applied on Bonan oilfield. The results showed that the functional injection increasing displacement agent could not only adsorb on the oil-water interface and reduce the oil-water interfacial tension，but also emulsify crude oil and remove the oil film. The cationic component took water as the transfer medium to form a molecular film on rock surface，which could stabilize clay，improve the wettability of rock surface，reduce injection pressure and improve water injection recovery. The functional injection increasing displacement agent had good anti swelling effect，depressurization，injection increasing and oil displacement effect when its concentration was low. In the field test of pressure flooding，the injection capacity of water injection wells and the oil production capacity of corresponding oil wells were significantly improved.