Based on the analysis of structure styles which had been adopted widely on domestic and foreign large tonnage vacuum arc remelting(VAR) furnaces at present,this paper pointed out some shortcomings and deficiencies existing in these types of VAR furnaces, and put forward a new double chambers type VAR furnace structure. This paper also gave a detailed introduction on the main body structure design，main technical features and performance index of the SZHL8 double chambers type VAR furnace, especially focuses on the main technical issue being necessary to solve during development, including double chambers sharing one set of rectifiers, structure optimizing of water cooling furnace chamber,cooling system of crucible, intelligent melt rate control system and partial pressure real time control system.