The oilfield water injection corrosion inhibitor was synthesized by reacting different long-chain fatty acids with tetraethylenepentamine, and the optimal synthetic conditions were obtained using orthogonal experiment method. Static coupon weight loss method was adopted to evaluate the inhibitor performance and the effects of the temperature and concentration on the performance were studied. The results showed that the corrosion inhibitor had good performance at the conditions of concentration as 800 mg/L and relatively low temperature.