The invention discloses an electrode spacing adjusting device. The electrode spacing adjusting device is mainly used for achieving the effects that the adjusting device is not affected by water scalewhen being immersed in water for use, and timely adjustment is achieved. The electrode spacing adjusting device comprises a fixing plate, an adjusting wheel, an adjusting knob and heating electrodes.The electrode spacing adjusting device has the beneficial effects that due to the fact that the adjustment of the distance between the electrodes is achieved by taking a supporting shaft as the circlecenter and enabling the two electrodes to swing in opposite directions by uniform angle, so that the torque required to be overcome through the adjusting wheel is relatively small, the adjusting device can be completely immersed in the water and does not need to worry about the friction force formed by the ''water scale'', and moreover, the adjusting wheel can be installed at any angle, so that the application range of the adjusting device is widened.