Abstract: To increase the injection intensity and efficiency, a test stand is designed for the axial injection system of 20～100 MeV compact cyclotron so as to implement the experimental study. The design aspects of test stand, including the optics of the beam line, the elements design etc., are described in the paper.Mostly the elements selection for the beam transportation from the H - source to the central region of the cyclotron, the matching calculation and the elements design are considered. To investigate the injection system of 22 MeV and 70 MeV cyclotrons experimentally by the test stand, the design goal is to keep the layout of injection line, the dimensions of elements,the operation parameters as close as possible so that the setup of the stand is more easily. The designed system can meet the need of the H - beam injection for the cyclotron from 20 MeV to 100 MeV though the dimension of the solenoid, which is installed in the main magnet of the machine, should be changed due to the different size of the magnets.