Papermaking sludge (PMS) and iron-based waterworks sludge (IBWS) was used as raw materials to prepare magnetic dual sludge biochar (MDSBC) using the one pot method. After being characterized by SEM, N2 adsorption-desorption, XRD, FTIR, XPS, and vibrating sample magnetometer, the static adsorption of ciprofloxacin hydrochloride (CIP) in water by MDSBC was studied. The results showed that when the mass ratio of IBWS: PMS was 1:2.5, MDSBC prepared by pyrolysis at 500 ℃ in N2 atmosphere had desirable CIP adsorption capacity and good magnetic separation performance. Within the initial pH range of 3-9, the adsorption capacity at pH 3 was the lowest due to electrostatic repulsion, which is 28.13 mg/g; The adsorption capacity was highest at pH 5, which was 33.65 mg/g. The adsorption process of CIP by MDSBC fitted the pseudo-first-order kinetic model. The adsorption isotherm model conformed to Langmuir model, and the adsorption process was spontaneous and exothermic. Aqueous Cl- and SO42- prompted CIP adsorption slightly, while PO43- could significantly inhibit the CIP adsorption with the rising PO43- concentration. After 5 cycles of reuse, the adsorption capacity of MDSBC decreased by 12.5%. The mechanism analysis indicated that electrostatic adsorption, chemical adsorption, hydrogen bonding, and π-π interaction were involved in the adsorption of CIP by MDSBC.