To analyze the main factors controlling the effectiveness of corrosion coupon monitoring，a three-factor，three-level orthogonal experiment covering field conditions was designed using a multiphase flow corrosion loop (MPFC).The orthogonal experiment was verified through Fluent finite element simulation analysis.The MPFC test results indicated that the average corrosion rate of the coupons was positively correlated with temperature，flow rate and installation depth，and it was observed that the corrosion rate of the coupons was higher than that of the pipe wall.In the Fluent finite element simulation，both the surface flow velocity on the coupon and the length of the recirculation zone were positively correlated with coupon depth.Turbulent kinetic energy along the flow direction (x-axis) showed a pattern of rapid increase followed by gradual decrease.Additionally， the shear force on the coupon and the corrosion monitoring error were positively correlated with temperature， flow rate and installation depth.Based on the results of the orthogonal experiment analysis， the controlling factors for the effectiveness of corrosion coupon monitoring were ranked as installation depth＞flow rate＞temperature.