The invention belongs to the technical field of inorganic chemical industry, and particularly relates to a method and equipment for producing liquid sulfur dioxide through sulfur trioxide and sulphur. The method comprises the following steps: concentrated sulfuric acid or fuming sulphuric acid is fed into a reaction kettle, then liquid sulfur trioxide and liquid sulphur are fed into the reaction kettle, and stirring for reaction is performed; mixed gas generated through reaction enters a packing reaction tower filled with blocky solid sulphur for reaction, then mixed gas generated through reaction sequentially enters a purification tower and a pickling tower for purification absorption, and then is cooled to be liquid sulfur dioxide through a condenser. The equipment comprises the reaction kettle, wherein the reaction kettle, the packing reaction tower, the purification tower, the pickling tower, the condenser and a liquid sulfur dioxide storage tank are sequentially connected with one another; the reaction kettle is connected with a blow-down pump. Compared with the conventional pure-oxygen sulphur-burning method, the method has the advantages that multiple complex filtering equipment and oxygen generating equipment with relatively high cost are not required, the raw materials are cheap and easy to obtain, and are not required to be processed, the processes are simple, the technology is stable and reliable, the production running cost is reduced greatly, the product quality is high, and the method is suitable for industrial production of the liquid sulfur dioxide.