Electroslag remelting system for realizing air pressure balance and gas-liquid mixed condensation and control method

The invention relates to an electroslag remelting system for realizing air pressure balance and gas-liquid mixed condensation and a control method, a gas jacket is arranged on the inner layer of the side wall of a crystallizer, so that the inner wall of the crystallizer is subjected to air cooling while the internal and external pressure balance of the copper inner wall of the crystallizer is realized; the cooling water jacket is arranged on the outer layer of the side wall of the crystallizer, on one hand, the inner wall of the crystallizer is indirectly cooled through gas in the cooling gas jacket, and on the other hand, the inner wall of the crystallizer is directly cooled through radiation; the cooling water jacket is divided into a plurality of cooling areas in the height direction and the circumferential direction of the crystallizer, and regional accurate cooling is achieved. Prediction and accurate control of the temperature gradient of the electroslag remelting solidification area are achieved throug