Given the advantages of conductive hierarchical chiral nanocomposites for microwave absorption, a templated method was utilized to grow ZIF-67 in situ on helical CNTs (HCNTs). Due to the peculiar helical morphology and size of HCNTs, ZIF-67 exhibited distinctive growth features and pyrolysis features compared to those on planar substrates. In this work, the peculiar morphology was used to separate the nucleation and growth rate on the HCNT surface edges and grooves. Combining the control of solution concentration, reaction time and pyrolysis temperature of ZIF-67, hierarchical helical C/Co@CNT nanocomposites were successfully prepared at a 30 mM Co²⁺ concentration and a 700 °C pyrolysis temperature. Different from the traditional core–shell structure, this special nanomaterial possessed continuously helical doped carbon belt layers containing embedded Co particles deposited along the HCNT surface edge regions and exhibited a helically conductive path. These growth and pyrolysis mechanisms were explored in detail. With this special structure and composition, the abundant heterogeneous interface, rich defective polarization, good conduction loss, double cross polarization and good magnetic loss synergistically endowed it with an excellent microwave energy dissipation capacity. As a result, C/Co@CNT nanocomposites demonstrated excellent microwave absorption properties. When the thickness is 3.8 mm, the minimum reflection loss is −56.8 dB. The effective absorption bandwidth (RL ≤ −10 dB) is 4.8 GHz with a thickness of 1.6 mm and a filling rate of 25 wt%. We not only prepared an excellent electromagnetic wave absorber with a hierarchical helical structure, but also provided helpful guidelines for designing such a special nanostructure.