Laser cladding technique can save resource consumption, achieve rapid manufacturing and damage repair of high-end parts/components, and thus promote environmental sustainability. However, in most cases, the surface finishing of cladding parts/components cannot meet the requirements of engineering applications, and thus post-cladding processes are required. Here, a sort of post-cladding treatment, that is, ultrasonic warm burnishing coupled with sequent heat treatment (UWB/HT), was proposed and employed to treat coatings after laser cladding. Especially, based on experimental data, a prediction model of surface roughness of the studied Fe-based cladding coating was built. ANOVA and RSM methods were employed to investigate the effect of heating parameters, i.e, heating temperature and heat holding time, on roughness of laser cladding coatings treated by UWB/HT. According to result, the surface roughness of the studied coating was positively related to heating temperature. For instance, at a same holding time, the roughness values of coatings treated at 100 ℃, 250 ℃ and 400 ℃ were Ra 0.237 μm, Ra 0.158 μm and Ra 0.096 μm, respectively. Therefore, it was proved that UWB/HT process could further decrease coating roughness in comparison to traditional ultrasonic burnishing without heating treatment. However, in contrast, a long holding time was supposed to result in slight increase of coating roughness. For instance, at a same heating temperature, the roughness values of coatings treated at 0.5 h, 1 h and 2 h were Ra 0.156 μm, Ra 0.164 μm and Ra 0.170 μm, respectively. The warm plasticity of metal materials resulting from high temperature was responsible for the roughness decrease of coating treated by UWB/HT. Meanwhile, longer holding time led to somewhat deformation recovery of burnished coating and therefore resulted in slight roughness increase. According to ANOVA result, heating temperature had a more significant effect on coating roughness than holding time. Within experimental scope, the optimum parameter combination was 400 ℃ heating temperature and 0.5 h holding time, under which a least roughness value of Ra 0.089 μm was achieved.