Abstract: Herein,we addressed the drafting and design of the pumping system for large-sized,ultra-high-vacuum(UHV) torus chamber in China Fusion Engineering Test Reactor(CFETR).First,the effective pumping-speed for fuel particles of cryo-pump set,installed at the outlet of the lab-built Divertor,was theoretically analyzed in particles equilibrium method and numerically simulated; and the optimized number and alignment of cryo-pumps,with the pumping-speed of 43 m³/s,were determined; second,the helium-ash extraction capacity of and tritium inventory in the cryo-pumps were analytically calculated and experimentally evaluated; and finally,the pumping-speeds of UHV-maintaining and roughing pump-sets were calculated,to meet the stringent requirements on the ultimate pressure of Torus and for their design optimization.We suggest that the drafting and design of the pumping system for Torus chamber be of some technological interest in the accomplishment of CFETR project.