Microwave absorption materials with high-effective, broad band and thin thickness have attracted a lot of attention of researchers. In this work, the flaky NdxCe2-xCo17 alloy powders were prepared by vacuum arc melting and high energy ball milling method. The influences of Nd content and matching thickness on phase composition, morphology, electromagnetic parameters and microwave absorbing property are studied by relevant equipments. The microwave absorption of Nd0.3Ce1.7Co17 powders were efficiently optimized generating a maximum RL of -32.36 dB and 4 times extension of effective bandwidth. Moreover, adjusting of Nd content successfully realize the optimization absorption of Ce2Co17 alloy powder. The absorption peak shifts to lower frequency region with the increasing Nd content and the maximum RL of Nd0.3Ce1.7Co17 powder can reach about -30.53 dB at 7.28 GHz at a given thickness of 1.8 mm with the effective bandwidth of 2.24 GHz, indicating that the Nd-Ce-Co alloy can be used as an ideal absorbing material in C-band with low thickness, broad band and high-effective.