This study analyzed the techno‐economic feasibility of a biomass conversion process enabled by high‐solid loading deep eutectic solvent (DES) pretreatment for the co‐production of 2,3‐butanediol (BDO), furfural, and technical lignin. Aspen plus was used for process simulation; economic analysis models were developed to evaluate commercial potential; sensitivity analysis was carried out to evaluate the effects of key parameters on the production cost of 2,3‐BDO; and Monte‐Carlo simulation was used for uncertainty analysis. Two cases of high‐solid loading pretreatment (20% versus 27%) for DES pretreatment were compared. The process simulation results indicate that 78–79% of cellulose, 63–70% of xylan, and 40–44% of lignin in raw switchgrass are converted into 2,3‐BDO, furfural, and technical lignin, respectively. The minimum 2,3‐BDO selling price (MBSP) of these two cases is estimated to be 1703–1736 $ ton−1, which is about half of the current 2,3‐BDO market price. Sensitivity analyses show that the prices and recycle ratios of acetone and methyl isobutyl ketone (MIBK) have larger impacts on the MBSP, which indicates that further technical improvement should focus on reducing their consumption. The uncertainty analysis indicates that 20 and 27% solid loading systems have similar confident intervals, with 90% confidence interval of MBSP ranging from 1450–1990 $ ton−1. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd