Abstract: On the basis of comprehensively evaluating the homemade xanthan gum and polyacrylamide,chose the low hydrolysis water soluble polyacrylamide to prepare the oil displacement agent,then,used the prepared polymer to have conducted displacement test in the low permeability and high salinity reservoir of Maling oilfield. Displacement test results indicated:when the polyacrylamide with 10% degree of hydrolysis was used together with the chemical stabilizer,the salt tolerant property and the thermal stability of the polyacrylamide could accord with the oil displacement test requirements of Maling oilfield. After having conducted physical analog and numerical simulation on polymer flooding in Maling oilfield,the optimal polymer injection parameters were determined. In addition,polymer injection test was conducted in single well in middle unit of Maling oilfield.