The invention discloses a deep grounding electrode electrolysis reaction simulation system and a method which are used for simulating and analyzing electrolysis reaction of a deep grounding electrode. The deep grounding electrode electrolysis reaction simulation system comprises a reaction vessel comprising a connecting box and two reaction tubes of which the bottom ends communicate with the connecting box hermetically, and the top of each reaction tube is provided with a sealing end cover; an anode feed rod and a cathode feed rod are arranged on the two reaction tubes respectively; at least one reaction tube is internally provided with a removable sealing bulkhead which is used for dividing the corresponding reaction tube into a plenum chamber and a reaction chamber located below the plenum chamber, and the feed rod arranged in the reaction tube with the sealing bulkhead is located in the corresponding reaction chamber; the sealing bulkhead is provided with an exhaust pipe in a run-through manner, and the exhaust pipe is provided with a plurality of blowholes; the anode feed rod is connected to the anode of a DC power supply, and the cathode feed rod is connected to the cathode of the DC power supply; two gas collecting devices communicate with the tops of the corresponding reaction tubes.