A relationship was studied among D/Pd gas-solid system current, pressure and producing excess heating in this paper. The results indicated that when the pressure of deuterium is at 9 × 104 Pa, electric current is 8 A and lasting heat is 40 days, the superheating energy is 280 MJ, the maximum superheating power is 80 W and averaging to each palladium atom energy for the superheating energy is 1.7 × 104 eV. Analysis of the sample by SEM (scanning electron microscopy) and EDS (energy dispersive spectrometry) found that after the current triggering the surface of sample was changed and new elements such as Pb, Sn, Ca, and Ag appeared. The results suggested that the superheating appeared come from a nuclear transmutation.