High-speed digital video acquisition is important for the image inspection in ballistic trajectory.How to optimize real-time characteristic of recording system is discussed. Contraposed windows operation system′s non-real-time characteristic, several methods are proposed to reduce non-real-time characteristic of operation system. Thread pool model of system is proposed to enhance throughput ratio of recording task.Scheme of losing image ratio detection is establised. Testing result shows that grabbing velocity breaks through 50 MBps and the whole system works steadily.