The work aims to improve the corrosion resistance of CT90 coiled tubing and the efficient of the lase cladding. The Ni/316L cladding layer was deposited on CT90 coiled tubing via high-speed laser cladding. The microstructure of cladding was addressed by scanning electron microscope (SEM) and energy dispersive spectrum (EDS). The elentrochemical workshop was employed to test the resistances of general corrosion and pitting corrosion of the cladding and then the corrosion morphology was represented through SEM. The Ni/316L cladding layer with thickness of 200 μm could be deposited on CT90 coiled tubing after once scanning. The cladding layer contained 50 μm thick diffusion region and 150 μm thick coating. The cladding layer was dense and the porosity was only about 0.4%. In addition, the dilution rate was approximately 1.7%. The columnar grains in cladding mainly grew perpendicular to the interface of cladding layer/matrix, and there were a few equiaxed grains and slatted grains around the surface of cladding layer. Compared with the inner of grain in coating area, the Cr element content at grain boundary in coating area decreased about 1.2%. The corrosion potential of Ni/316L cladding layer increased about 0.55 V after high-speed laser cladding. Additionally, the corrosion current density decreased about 95%. The pitting potential of the cladding layer was about 0.34 V. The CT90 corrosion was seriously after electrochemistry test, while the most regions of cladding still remained the morphology before test except a few local corrosion areas. The corrosion regions of cladding surface exhibited faveolated morphology. The high-speed laser cladding not only can deposit the coating with characteristics of low porosity, densification, low dilution rate, but also dramatically improve the efficiency of laser cladding. Both the general corrosion resistance and the local corrosion resistance of CT90 coiled tubing improves dramatically via 316L/Ni coating deposited by high-speed laser cladding. Meanwhile, the corrosion mode changes after deposition of 316L/Ni cladding.