Abstract: Based on "2+3" theory of profile control and water shutoff,research on large dose multi-blocks deep profile control and oil displacement technique is put forward to improve injection profile and production profile.Selective water shut off action of water shutoff agent,effect of permeability on injection pressure,movability of water shutoff agent are researched,and multi-block design of water shutoff agent,particles diameter selection of water shutoff agent are performed.Results of experiment indicate the dual effect of water shutoff and oil displacement is gained through injecting large dose,low concentration,multi-block,expansive water shutoff agent.Large dose multi-blocks deep profile control and oil displacement experiments of two wells are performed in the Block-17 of Pingfangwang Oilfield.After profile controlling,average water injection amount reaches 86.5 m3/d,average water injection pressure is enhanced by 3.5 MPa,5 wells out of corresponding 10 wells take effect,and daily increasing oil amount reaches 17 t in the initial stages of taking effect,in other words,increasing oil effect is good.Moreover,technique reference is provided to research on enhancing effect of profile control and oil displacement in large-heavy layer and multicycle profile control technique.