A new and simple method is established to prepare crosslinked polyamide complexes (cPACs) through Michael addition and coordination. A linear polyamide with terminal acrylamide groups (t-AA-PA) was prepared by a Michael addition of N,N′-methylenebisacrylamide and piperazine. Crosslinking reaction of the t-AA-prePA was conducted with different aliphatic diamines, and three crosslinked polyamides containing piperazine rings (P-cPAs) were synthesized. Differential scanning calorimetry and wide angle X-ray diffraction verified the crystallization feature of P-cPAs. They possessed Tg around 78 °C, Tm around 203 °C, and tensile strength up to 24 MPa. After P-cPAs were coordinated with Co2+ ions and dried fully, cPACs with removed chelating water (r-cPACs) were prepared. Chelating P-cPAs with Co2+accompanied a color change, the increase in Tg, and the loss of crystallization ability. When r-cPAC-Co2+s were immerged in water or methanol, an evident solvatochromic change was observed, and a reversible color change occurred after heated above 80 °C.