The apparent viscosity change of polyacrylamide (HPAM) solution with shearing time was studied by control stress rheometer at 30℃ and different shear rate, which reflected the influence law of shear flow conditions on the viscosity of HPAM solution. According to the site conditions, shear rate and shear time of different concentration of HPAM oil displacement agent in pipeline flow were obtained by calculating. The results showed that when the shear rate was 3.11—7.76 s^-1 and shear time was 55—22 min, the viscosity of high concentration (5000 mg/L) HPAM oil displacement agent increased slightly with the extension of shear time. The adhesion loss rate per unit time was -0.43%/h—-0.91%/h. In the process of conveying, pipe flow shear had no effect on the viscosity loss of high concentration HPAM oil displacement agent. When the shear rate was 36.84—92.10 s^-1 and shear time was 2.26—0.90 h, the viscosity of low concentration (1000, 2000 mg/L) HPAM oil displacement agent gradually reduced with the extension of shear time. The adhesion loss rate per unit time was 0.08%/h—0.86%/h and 0.07%/h—0.30%/h, respectively. In the range of low concentration, the influence of shear history on the viscosity and adhesion loss rate of HPAM oil displacement agent increased with decreasing concentration of HPAM flooding agent. Increasing concentration was helpful to reduce the adhesion loss rate of oil displacement agent.