Abstract: The technological parameters of dealing with waste acid produced by synthesizing nitroglycerine/triethylene glycol dinitrate (NG/TEGDN) multi-nitro ester propellant by means of thermal decomposition after dilution were investigated.Results showed that the treated waste acid was an ideal dilution medium, and the optimal choice of flow ratio of treated waste acid/waste acids afeer and before treatment was 2.5~3.0, the treatment temperature 150~180℃, the vacuum degree 0.02~0.04 MPa, and the waste acid flow 1.8~2.0 L/min. The ester content of treated waste acid by this method was less than 0.5%. Therefore, the treated waste acid could be stable up-to-standard and be discharged, and the safe uninterrupted producing wouldn't be disturbed.