In this paper, a type of thin planar absorbing structure of Jerusalem cross slot (JCS) is presented, which has the virtue of wider bandwidth and broader adjustment range. The absorption frequency band can be flexibly adjusted by the slot parameters. The influences of various structure parameters of JCS, incident wave polarization and variation of incident angles on the absorption characteristics are analyzed to provide guidance on theoretical design for practical application. The validation and effectiveness of the proposed design are conducted by using waveguide simulation and measurement.