The invention provides a track vehicle side wall resistance spot-welding system and method. The track vehicle side wall resistance spot-welding system comprises a resistance welding machine, wherein the resistance welding machine comprises a wall board electrode and a framework electrode which are arranged oppositely and further comprises an electric control cabinet and an electrode position detecting device, wherein the electrode position detecting device comprises a supporting sleeve, an outer sleeve, an inner sleeve, a first spring, a second spring, a first position sensor and a second position sensor. One side of the outer sleeve is provided with a first detection hole, the other side of the outer sleeve is provided with a strip-shaped hole along the axis, the inner sleeve is provided with a second detection hole, and the second position sensor is further located in the strip-shaped hole. When the electrode position detecting device is located in an initial state, the first position sensor and the first detection hole are opposite, and the second position sensor and the second detection hole are opposite. The track vehicle side wall welding quality is improved through the track vehicle side wall resistance spot-welding system.