The invention relates to a pressure reducing and injection increasing agent used for a flooding well, which is applicable to water injection of an oil well. The invention is characterized in that the pressure reducing and injection increasing agent comprises the following ingredients according to the parts by weight: 30-42 parts of lauric acid monoethanolamine, 2.5-4.5 parts of L-alinebenzylestertosilate, 5.5-7.5 parts of C8-C10 alkylglucoside, 0.5-1.0 part of sodium nitrite, 0.5-1 part of Vitamin A, 0.05-0.1 part of fluorocarbon surfactant FN-2, 25-35 parts of methanol, and 15-35 parts of water. The invention has the effects that the pressure reducing and injection increasing agent can reduce oil-water interface tension, change wettability of rocks and inhibit clay swelling, thereby reducing wellhead pressure of the flooding well by 5-15 percentage points, so as to improve the seepage ability of injected water; therefore, the pressure reducing and injection increasing agent realizes pressure reducing and injection increasing for a low-seepage oil well and can inhibit bacteria growth.