Abstract: with the continuous development of polymer injection blocks, the situation of polymer injection wells becomes more and more complex. At present, most of the polymer injection units are second level or third level reservoirs with serious reservoir heterogeneity, prominent inter-layer conflicts and large permeability differential. Therefore, the technology of polymer surface mass and pressure separation injection is equipped to meet the requirements of the polymer mass and pressure separation injection in the second level and third level oil reservoirs. The formation is sealed by concentric dual injector string, forming three independent water injection channels, and low shear injector is installed in the ground face of high permeability formation to produce throttling pressure difference and control flow rate. The quantitative shear injector is installed in the low permeability layer to increase the viscosity loss rate of the polymer and reduce the molecular weight of the polymer, so that the molecular weight of the polymer matches the permeability of the formation. It not only simplifies the test preparation process, shorts the test time and reduces the test cost, but also makes the test deployment timely and accurate, ensures the timeliness of the geological plan, and makes up for the shortcomings of the existing ground mass and pressure injection process, and further improves the oil displacement effect of polymer injection.