The invention provides a brick joint control tool used for fully laying carbon bricks on the furnace bottom of a blast furnace and the using method of the brick joint control device. The brick joint control tool comprises a screw wedge and a screw support, the method used for fully laying the carbon bricks on the furnace bottom of the blast furnace comprises the following steps: during brick entering and pre-laying, using the screw wedge for wedge-caulking to the two ends of each carbon brick to be built in each row, during carbon brick laying, placing the screw support on the two sides of a brick in a center row so as to tightly prop the carbon brick to be built, removing the screw wedge, and removing the screw support. The brick joint control tool provided by the invention has the advantages that the material access is easy, the manufacturing is simple, brick joint control is convenient, and brick joint quality can reach the standard easily; adjustment can be performed arbitrarily, the probability of damage is low, and repeated and long-term cycle use is facilitated. Therefore, the laying quality is improved, and the construction progress is accelerated; and timber for manufacturing wooden wedges and the cost for purchasing screw jacks in the traditional process are reduced greatly, therefore, the construction cost is lowered, and economic benefits are improved.