The theoretical performance of a pulsed HF/DF optical resonance transfer laser (ORTL) is presented. The key reaction of HF/DF is the HF-DFV-Venergy transfer reaction, but its rate constant has not been accurately determined so far. Therefore, in order to precisely predict the CW HF/DF ORTL experiment, the rate constant of the HF-DFV-Venergy transfer reaction is determined to be dependent on V2. The relationship between gas concentration (HF, DF, and He) and pumping condition (pumping intensity and pulse width) is determined to maximize the DF small-signal gain. As a result, it is found that the pumping HF laser lines of2.7-3.0mum are shifted to the ORTL lines of3.9-4.3mum at a low total pulse efficiency of about 0.1 percent.