Under the severe condition of high temperature and heavy load, electroplating chromium coating is extremely easy of premature spallation so that the service lifetime of components is dramatically reduced. Laser phase transformation hardening was used to pretreat the superficial layer of substrate before electroplating in order to improve bonding strength between the electroplating coating and the substrate and enhance the load endurance. The microstructure and interface of electroplating chromium coating were analyzed by scanning electron microscopy (SEM). The hardness variation of electroplating coating, phase transformation hardening zone, and substrate were analyzed. The ability resisting high temperature ablation was measured. The results showed that laser phase transformation hardening on the substrate could not only effectively promote the epitaxial growth of electroplating chromium coating, but also realize the gradient variation of the hardness from electroplating chromium coating to substrate. Consequently, the bonding was improved, the stress was alleviated, and the load endurance was enhanced. So the spallation resistance and the service lifetime of electroplating chromium coating were evidently enhanced. It was a main reason for the epitaxial growth of electroplating chromium coating that the refined quenching martensite was obtained, the dislocation density was evidently increased, and the surface activity was increased by laser phase transformation hardening.