Pressure-reducing injection-increasing agent and pressure-reducing injection-increasing method for water injection oil well

The invention discloses a pressure-reducing injection-increasing agent which contains hydrophobic modified cyclodextrin. The hydrophobic modified cyclodextrin contains modified groups which contain at least one type of first modified group and at least one type of second modified group. The first modified groups are hydrophobic groups and the second modified groups are hydrophobic groups containing hydrophilic functional groups. The invention further discloses a pressure-reducing injection-increasing method for a water injection oil well. The method includes the step that the pressure-reducing injection-increasing agent is injected in the water injection oil wall according to the pressure-reducing injection-increasing agent and the pressure-reducing injection-increasing method. Due to the fact that the pressure-reducing injection-increasing agent contains the hydrophobic modified cyclodextrin, the pressure-reducing injection-increasing effect on the low-permeability reservoir water injection wall is good. The hydrophobic modified cyclodextrin used in the pressure-reducing injection-increasing agent is simple in preparation process and suitable for being produced on a large scale.