As the ideal structure model and accuracy analysis of existing four-light-screen optical target cannot meet the requirement of engineering design and development,a common engineering structure model was developed,and the measurement formulas and error transfer formulas were deduced.The influences of different parameters,such as the impact location,target distance,light-screen intersection angles and the size of sensor area,to the position measurement accuracy of system were analyzed through simulation.A series of position measurement error analysis data were acquired.The structure and theoretical error estimate results of a practical four-light-screen optical target were given.The live-fire testing result shows that the X and Y position measurement errors of this four-light-screen optical target system in a 1 m×1 m sensor area are less than 2 mm,which is close to the theoretical analysis result,and the result verified the correctness of the proposed engineering model and effectiveness of theoretical analysis.This research can provide useful reference for practical design and accuracy estimate of four-light-screen optical target.