The unique layered structure and adjustable band gap of transition metal dichalcogenides (TMDs) have prompted extensive investigations into their potential for electromagnetic wave absorption (EWA). Vanadium selenide (VSe2), a notable representative of TMDs, has a larger interlayer spacing (6.1 Å) and higher conductivity (1 × 10-3 S/m), which has high advantageous in EWA applications. However, the existing research on the use of VSe2 for EWA remains relatively limited. Herein, a flower-branch-like carbon microtube/vanadium selenide (CMT/VSe2) composite was successfully synthesized via a facile solvothermal method. This composite material is composed of flower-like VSe2 nanostructures integrated with carbon microtubes. Importantly, the EWA properties of this composite can be effectively tailored by adjusting the concentration of the VSe2 precursor. The CMT/VSe2 composite exhibited a remarkable minimum reflection loss (RL) of −60.54 dB in the Ku-band, with a matching thickness of 2.27 mm. Moreover, the effective absorption bandwidth reached 6.38 GHz. These results demonstrate the great potential of this CMT/VSe2 composite material as a highly efficient EWA material. Furthermore, this work broadens the application of two-dimensional TMDs in the area of EWA.