The invention relates to the technical field of copper content detection and particularly relates to an amino-functionalized ionic liquid-carbon nanotube based copper ion selective electrode and a preparing method thereof. An electrode filling liquid comprises an amino-functionalized ionic liquid, a solid ionic liquid and carboxylated carbon nanotubes in a weight ratio of 10-40:10-40:1-3. The preparing method includes inserting a copper wire into a glass tube, fixing the copper wire to allow one end of the copper wire to be flushed with the glass tube and the other end to extend out of the glass tube, and adding the electrode filling liquid into the glass tube. Electroconductibility, sensitivity and selectivity of the copper ion selective electrode are greatly improved, and detection is shorter in time and higher in precision. The preparing method is simple, convenient, simple and suitable for large-scale production.