The invention provides a coupling technology adopting lignite-gasification gas production and dry distillation upgrading. A coal gasification device and a coal-produced semi-coke dry distillation device are connected in series for use, high-temperature synthesis gas produced from coal after gasification in a gasification furnace directly enters a dry distillation furnace, is taken as a dry distillation heat-carrying gas and is sufficiently contacted with the coal in the dry distillation furnace, H2O and CO2 in the synthesis gas are contacted with a hot carbon material for further reaction, effective gas composition in the synthesis gas is increased, and a semi-coke product, coal tar and dry distillation gas are obtained through pyrolysis and dry distillation upgrading of the coal. The semi-coke product is collected from the bottom of the dry distillation furnace, a mixture of the coal tar, the dry distillation gas and the synthesis gas is collected from the top of the dry distillation furnace, and a coal tar product and a synthesis gas product are obtained through cooling separation. Compared with a simple lignite-gasification gas production technology, the effective gas composition of the produced synthesis gas is higher, the CO2 emission proportion of a traditional coal gasification technology can be reduced, the heat of the whole technological procedure is sufficiently utilized, additional heat input is not required for semi-coke production through dry distillation of the coal, and the energy utilization efficiency is high.