Abstract: Crochet process was specially applied to combine activated carbon fibers (ACF) with glass fibers (GF) to improve the designability and complexity of frequency selective surface (FSS), ACF crochet structure circuit screen carbon fibers/epoxy(ACF/EP) composites were prepared. The effect of different knitted structure and ACF mass fraction to microwave absorbing performance of composites was discussed. The results show that the maximum reflection loss (RL) of both 4-needle-date-shaped FSS CF/EP composites with 100% CF and 16-needle-date-shaped FSS composites with 50% CF are higher than -50 dB, in addition, the effective absorption bandwidth (RL<-10 dB) could reach to 10 GHz. With complex crochet design, the porous structure of CF/EP composites increase, effective absorption bandwidth(RL<-10 dB) broaden, and 4-needle-date-shaped structure with more irregular aperture has excellent microwave absorbing property. Ideal CF/EP microwave absorbing composites will be obtained by combining the suitable mass fraction of chopped CF and knitted structure.