Concept design of CFETR superconducting magnet system based on different maintenance ports

•This article discussed the concept design of the magnet system of CFETR based on different maintenance port cases.•The major and minor radius of plasma is 5.7m and 1.6m, and the central magnetic field was designed as 4.5/5.0T.•The different maintenance ports design have little impact on the design of TF and CS coils’ design, but have certain impact on the PF coils’ design.