Abstract: Since traditional measurement can only measure the parameters of information field at the beginning stage and terminal stage，complete information field parameters during whole guiding process is not available and the missile guidance performance can not be accurately evaluated. To solve this problem, the guiding distance measurement of the information field was realized by using large aperture zooming collimator and precision grating ruler. The information field was detected by optical fiber target and PIN detector array. The signal was processed according to the existing mathematical model and the information field parameters during guiding process were obtained. Results indicate that the test accuracy of command test reaches 0.01 unit command, the accuracy of irradiance measurement reaches 5% and the bore-sight accuracy reaches to 4.89.