Abstract: Wen- Wei oilfields are complex fault block oilfield,reservoir heterogeneity is serious,the level of formation permeability is big.Years of development of water injection caused more serious heterogeneity of water injection profile,which influenced influence oilfield development level enhancement. Temporary plugging acidization technology means by pumping temporary plugging additive to form low permeable filter cake in high permeability layer and parts of middle permeability layer,then cause the acid liquor to flow into middle and low permeability layer,which can relieve middle and low permeability layer damage effectively,improve water injection profile,enhance acid liquor utility.With the study and application of temporary plugging acidization technology, grain water-soluble temporary plugging additive had been screened through experiments and it has been applied 5 well times,success ratio is 100%,effectiveness is 87%.