To address the remanufacturing difficulties of QT700 nodular cast iron gear， such as the decrease of surface hardness， the accumulation of chill microstructure at the interface， the easy cracking of the cladding layer， and the occurrence of porosity defects in the cladding layer， new composite process of laser cladding preparation and laser quenching to improve hardness is proposed. The FeCrNiCu alloy is chosen for its similar chemical composition and excellent mechanical properties （e.g.， hardness）. We prepare cladding layer on QT700 ductile cast iron gear surface； the good mechanical properties of the remanufactured coating are verified by experiments that include analysis of cladding layer microstructure evolution， surface hardness comparison， and evaluation of friction and wear performance. Results of these experiments show that the coating has good fusion， without pores， cracks and other forming defects； the microstructure is presented as a remarkable laser cladding rapid condensation structure. After quenching the top of the cladding layer， the equiaxed grains are finer and the grain size is reduced. Dentritic crystals in the middle part of the cladding layer are refined， and parts of the branches are separated. The size of cellular crystals at the bottom of the coating basically keeps the shape after cladding， but the chill microstructure at the interface is transtriated to partial melting and intermittent separation. After cladding， the microhardness of the cladding layer is about 473?589 HV， which is increased to 666?735 HV after quenching； the friction coefficient of the cladding is 0.15?0.25， optimized to 0.05?0.15 after quenching. This study provides process and method reference for laser remanufacturing of nodular cast iron.