Magnetic refrigeration based on magnetocaloric effect (MCE) is considered to be a new generation of green refrigeration technology. However, the corrosion of MCE materials caused by water-based heat transfer fluids hinders its long-term service application. Traditional compositional regulation method is difficult to ensure a balance between large MCE and high corrosion resistance. Herein, a Ni-electroplating method is proposed to significantly improve the corrosion resistance while remain the high MCE in typical La(Fe, Si)13-based (LFS) materials. The self-corrosion current density of LFS decreases by an order of magnitude from 2.64 × 10−6 A cm−2 to 5.12 × 10−7 A cm−2 after nickel coating. Besides the protection of nickel coating, a nanoscale oxide passivation film is formed on the nickel coating surface after immersion in deionized water, which further protects the sample from corrosion. The LFS/Ni shows a very low corrosion rate of 0.0347 g m−2 h−1 after immersion for 60 days, ≈80% lower than that of pure LFS. Moreover, the high thermal conductivity (λ) of Ni also improves the λ of LFS/Ni 3 times higher than the one before coating. Compared with benchmark Gd and other LFS materials with corrosion modification, LFS/Ni exhibits excellent comprehensive performance in all aspects of MCE, suggesting nickel-electroplating as an efficient method to promote the long-term application of magnetic refrigeration.