Three ternary Laves phase-based eutectic alloys CrFeNbx(x = 2.0, 2.35, 2.7) were designed successfully by combining thebinary phase diagrams and thermodynamics calculations. With the increasing Nb content, the solidified microstructuresevolved from the primary (Cr, Fe)2Nb plus the eutectic (Cr, Fe)2Nb/Nbss in the CrFeNb2.0,via the full eutectic (Cr, Fe)2Nb/Nbss in the CrFeNb2.35,and finally to the primary Nbss plus the eutectic (Cr, Fe)2Nb/Nbss in the CrFeNb2.7. The full eutectic(Cr, Fe)2Nb/Nbss of the CrFeNb2.35was found with outstanding thermal stability, and the lamellar eutectic was quitestable even under the heat-treatment of 1273 K/48 h. The compression strength and fracture toughness increased firstly anddecreased subsequently with the increase of Nb content, which reached their maximums of 2.54 GPa and 18.25 MPa·m1/2,respectively, in the CrFeNb2.35. The excellent combination of compression strength and fracture toughness in the CrFeNbx(x = 2.0, 2.35, 2.7) were attributed to the synergistic effects of Laves phase strengthening, interface strengthening, solidsolution strengthening, alloying toughening and Nbss phase toughening mechanisms.