The invention discloses a copper (II) coordination compound. A ligand (L+D)-PF is prepared from L-PF which is shown in the description and D-PF which is shown in the description according to a molar equivalent of 1 to 1, and the coordination compound is prepared from the ligand (L+D)-PF and copper (II) ions under a condition that the pH (Potential of Hydrogen) is 7 to 9. The invention also provides copper (II) hydrogel, a preparation method of the copper (II) hydrogel and application of the copper (II) coordination compound and the copper (II) hydrogel in aspects of carrying oxygen and releasing negative oxygen ions. The copper (II) coordination compound and the copper (II) hydrogel, provided by the invention, are capable of specifically identifying copper ions and are capable of carryingthe oxygen and releasing the negative oxygen ions.