This paper presents a mobile autothermal pyrolysis system for locally converting biomass feedstock into bio-oil that can be transported easily. The system includes a compact internally interconnected fluidized bed (IIFB) reactor, a biomass pretreatment facility, and a product recovery unit. On the basis of modified chemical kinetic models, the pyrolysis process of common forestry and agricultural residues in this mobile system has been simulated. The pyrolytic product distribution from simulation has good agreements with experimental results. Then, the techno-economic performance of the mobile pyrolysis system in China is evaluated and compared with other liquid biofuel production facilities, i.e., fixed biomass pyrolysis plants and Fischer-Tropsch liquids production via biomass gasification (BG-FT). The results indicate that the biomass feedstock cost of mobile pyrolysis systems can be effectively reduced. Compared with the fixed biofuel production plant, the labor cost is higher for the mobile plant. Though the fixed system has a lower initial investment, the mobile system has a lower biofuel production cost. Overall, the mobile pyrolysis system has a better long-term economy than the fixed plant, due to the larger profit. The mobile system can be profitable in the sixth year, which is one year earlier than the fixed ones.