The solid-state Ag / AgCl electrode was used to explore the ocean electric field. The effects of sintering technologies on the stability of electrode potential were researched. Four kinds of electrodes, which were respectively sintered to two temperatures of 380°C and 420°C by two heating methods of direct heating and phase-type heating methods, were prepared. Their surface morphologies, metallographic structures and the electrode potentials in 3.5% sodium chloride solution were analyzed to compare the stability of different sintering technologies. The results show that the electrodes sintered to 380°C by phase-type heating - insulation method have the best stability of potential, and potential difference of two electrodes is less than 0.02079mv/h.