NaHCO3 fine dry powder is an effective and green agent which is potential alternative of Halon 1301 used in current civil aircraft fire extinguishing system. In this paper, we built a fire extinguishing system for NaHCO3 fine powder agent based on a certain civil aircraft engine fire extinguishing system and performed the discharge test on it. The test result shows that the average flow rate of agent in this system is high enough, but the modification of current system is required to adjust agent splitting ratio for better performance. Preliminary agent concentration calculation demonstrates that current pipe network design can meet the agent concentration requirement.