A novel method using digital streak photography technique based on line-scan camera is proposed in order to circle out the problem in the digital improvement of the traditional streak facility in test range. The projectile’s stereo images were firstly collected by using a calibrated line-scan camera and a mirror, and then some special points were picked to compute the initial guess of the projectile’s velocity and attitude. The initial guess was further refined by using an optimization model established on the matching measure of the simulated and the real images contours. The speed and the attack angle were ultimately obtained. The accuracy of the estimation was experimentally tested.