Along with the development of oil and gas field, most blocks enter into the high water cut stage, and even very high water cut stage. Thin and low productive reservoirs are the potential reservoir by means of water flooding instead of the middle and high permeable reservoirs in low and medium water cut stage. With the imperfect injection-production relationship, low formation pressure, and low degree of producing reserves on thin and poor reservoirs. Taking the Xing6 east block of Daqing oilfield for example, the effective injection-production well spacing with different permeability is calculated by reservoir engineering methods, based on the flow tube model, the effective producing coefficient of different ratio of space between wells and rows for rhombus five-spot well pattern is solved. The results show that, the permeability of thin and poor reservoir is 12×10-3 μm2, and the corresponding effective injection-production well spacing is 180m, and the reasonable ratio of space between wells and rows is 1.8. The numerical models test and verify the results of theoretical methods, that is, the ratio is 1.8, the recovery factor is highest, the sweeping scope is large, and the water breakthrough time is earliest.