Abstract: In order to alleviate the contradiction between bandwidth extension and manufacturability of dual-band frequency selective surface (FSS), a method for bandwidth extension based on stubs loaded is investigated and analyzed. Firstly, the main factors of conventional means causing the above contradictions were analyzed. Secondly, the effect of different stubs loaded on the regulation of FSS is investigated, such as the resistance properties, shape and number of the loaded stubs, etc. Thirdly, the first/second passbands of FSS are extended based on stubs loaded which acted on grid/gap, respectively, and the alleviating effect of the stubs loaded on the above contradiction is analyzed in detail. Simulation and measurement results show that stub loaded technique can increase the bandwidth by 48.8% and 23.2% compared with the traditional bandwidth expansion method. It is shown that stubs loaded can effectively alleviate the contradiction between the bandwidth extension and machinability of multiband FSS, which provides theoretical guidance for the engineering practice.