The Beijing spectrometer III (BESIII) beam pipe is in the center of the BESIII, which is the detector of the upgrade project of Beijing electron and positron collider (BEPC II). Electrons and positrons collide in the BESIII beam pipe. According to the demands of the BEPC II, a key program of Chinese Academy of Sciences, the BESIII beam pipe is designed based on the finite elements analysis, The BESIII beam pipe is installed in the inner cylinder of the BESIII drift chamber. As a vacuum tube, the BESIII beam pipe is designed as 1 000 mm in length, 63 mm in inner diameter and 114 mm in outer diameter, respectively. The BESIII beam pipe consists of a central beryllium pipe cooled by EDM-1, the oil No.1 for electric discharge machining, and two extended copper pipes cooled by deionized water (DW). The three parts are jointed by vacuum welding. Factors taken into account in the design are as follows. (1) The wall thickness of the central beryllium pipe should be designed as small as possible to reduce the multi-scattering and improve the particle momentum resolution. And the wall thickness of the extended copper pipe should be designed as large as possible to protect the detectors from the backgrounds. (2) The BESIII beam pipe must be sufficiently cooled to avoid the damage and prevents its influence to the BESIII drift chamber (DC) operation. The inner surface temperature of the DC inner cylinder must be maintained at 293 +/- 2 K. (3) The magnetic permeability of the materials used in the BESIII beam pipe must be less than 1.05 H/m to avoid large magnetic field distortions. (4) The static pressure of the vacuum chamber of the BESIII beam pipe must be less than 800 mu Pa. The simulating results show that the designed structure of the BESIII beam pipe satisfies the requirements mentioned above. The structure design scheme is evaluated and adopted by the headquarters of BEPC II.