Abstract: The gain generator assembly is the core component which influences the recovered pressure of high energy deuterium fluoride(DF) chemical laser. The recovered pressure of DF laser exhaust gas using traditional gain generator assembly is about 6.7 kPa. A compact type of TRIP gain generator assembly was designed, with breakthroughs on the key techniques of running with high cavity pressure, primary stream curtain and restraining regurgitant stream of the laser cavity boundary wall. The recovered pressure of the DF laser was increased obviously. The test results show that the recovered pressure of the laser exhaust gas and the power flux were both increased effectively with the increase of the mass flow rate in the range of 1.3~3.3 g·s^-1·cm^-2. When the mass flow rate was 3.3 g·s^-1·cm^-2, the DF laser could operate efficiently at 26.7 kPa background pressure (air pressure of 10 km altitude).