It is known that electric fields (EFs) can affect the reaction kinetics. Notably, unlike the EFs at charged tips/electrodes which are directional, the interfacial electric field (IEF) at the surface of a water microdroplet continuously fluctuates over time. Hence, we first computed the barrier change under static and homogeneous external electric fields (EEF) applied along different directions, including the one coinciding with the reaction axis, to gain an upper limit of the catalytic effect on the DA reaction, then we examined the effect of the spontaneously fluctuating IEFs at the air-water interface.