Method for increasing injectability of reservoir polymer

The present invention relates to a measure for raising injectability of polymer. Said invention utilizes the regulation of electric environment of the water-soluble high-molecular solution, reversible control of molecular diffusion of polymer so as to effectively reduce size and solution viscosity of polymer molecule in the solution and can increase the injectability of polymer in the high-mediumpermeability oil deposit, and can implement oil displacement by polymer in low-permeability oir deposit. After the polymer solution is injected into the stratum, with the action of underground environment and change of electric environment, the original state of the polymer molecule is restored, solution viscosity also is restored so as to attain the goal of increasing injectability.