Water soluble temporary plugging agent for acidification of water injection well in low permeability oilfield, and preparation method and application thereof

The invention provides a water soluble temporary plugging agent for acidification of a water injection well in a low permeability oilfield, and a preparation method and an application thereof. The water soluble temporary plugging agent is prepared by mixing an inorganic salt, a dispersing agent and a particle size control agent uniformly, wherein based on a total weight of the water soluble temporary plugging agent, the content of the inorganic salt is 1%-20% (depending on application requirements); the content of the dispersing agent is 1%; the content of the particle size control agent is 0.2%-0.5%; the inorganic salt is selected one or more from sodium salicylate, sodium p-benzene sulfonate and sodium benzoate; the dispersing agent is selected one or more from methanol, ethanol, propanol and n-butanol; and the particle size control agent is selected one or more from isoamyl alcohol, n-hexane, EDTMPS and ATMP. The temporary plugging agent can effectively enter a reservoir stratum of the low permeability oilfield and be mainly applied in acidification works of the water injection well.