The collision relaxation of reaction products ground state to the excited state HF molecules is the key reason to reduce the non-chain pulsed HF laser energy. To solve this problem, the possibility of 3A type molecular sieve to eliminate the ground state HF molecules was analysised, and the experimental research was started as well. The result shows that, in the condition of non-utilization of any laser medium purity technology, the laser energy decreased by 52% after 103 laser shots is obtained at a pulse repetition rate of 50 Hz. So it can not satisfy the demand of high power, high repetitive frequency HF/DF laser in the future. After adding the 3A type molecular sieve adsorptive unit in the circulating pipe, the laser energy reduction is less than 15% after 103 laser shots is obtained for more than ten times, and the initial laser energy decreased by only 7.2%, this improves the stability of laser energy, and the useful time of laser medium. The 3A type molecular sieve is not only good at adsorb the ground state HF molecules, but also has the ability of regeneration and activation, it is expected to replace the ordinary chemical adsorption method.