Three copper-based nitrogen-carbon microspheres Cu-x/NC (x=1, 2, 3) were successfully synthesized by a one-step hydrothermal method using water-soluble low-molecular-weight chitosan (0.1 g) as carbon and nitrogen sources, and copper nitrate trihydrate (0.1802, 0.2899, 0.6522 g) served as copper sources. The morphology, composition and structure of Cu-x/NC were characterized by SEM, FTIR, XRD, Raman and BET. The adsorption performance of Cu-x/NC to tetracycline hydrochloride (TC) was investigated by static adsorption experiments. The parameters of adsorption kinetics, adsorption isotherms and adsorption thermodynamics were also determined. Cu-x/NC against ionic interference, pH stability, and cyclic adsorption properties of Cu-x/NC were detected. The results showed that Cu-x/NC exhibited a regular spherical structure with oxygen-containing and nitrogen-containing groups on its surface, and Cu elements were uniformly distributed. Cu-2/NC exhibited the maximum adsorption capacity for TC adsorption (1993.42 mg/g) at 25 °C of adsorption temperature and 24 h of adsorption time. The adsorption of TC by Cu-2/NC was in accordance with the Langmuir isotherm model and pseudo-second-order kinetic model, and the adsorption process was spontaneous and endothermic. The presence of NaCl in TC solution didn’t reduce the equilibrium adsorption capacity of Cu-2/NC toward TC, and TC solution pH=5.5 was most favorable for adsorption. In the 8-cycle adsorption tests, Cu-2/NC showed a relatively stable removal rate to TC (95.84%~86.67%). The main driving force for TC adsorption by Cu-2/NC depended on hydrogen bond, Cu cation bonding bridge, electron donor-acceptor interaction and electrostatic interactions.