The invention belongs to the technical field of nuclear fuel element pellet preparation and particularly relates to a method for preparing an annular uranium dioxide pellet.An annular female die, an annular lower punch and a core bar are fixed, the core bar is sleeved with the lower punch, the lower punch is sleeved with the female die, a supporting rod is arranged below the female die, and weighed UO2 powder is packed into an annular space formed between the female die and the core bar; an annular upper punch is placed into the annular space formed by the female die and the core bar, and a press is used for pressing the UO2 powder into a UO2 green body; the upper punch is taken out, a die releasing ejector block is used for releasing the UO2 green body, and the annular UO2 green body is taken out; the UO2 green body is sintered into a UO2 pellet; the outer diameter of the pellet is ground.The prepared UO2 annular pellet with the inner wall and the outer wall capable of containing cladding pipe can be applied to a single-cladding fuel assembly and can also be applied to a double-cladding fuel assembly.