Metal element (Nb, Er, and Gd) doped WOx powders were prepared via a one-step solvothermal method to enhance photocatalytic property of WOx, and they were used to enhance ultraviolet (UV) sensing performance of ZnO/glass surface acoustic wave (SAW) devices. Results showed that Gd-doped WOx has a better photocatalytic performance amongst the other doped WOx (Nb and Er), which can be explained using the different reductions of band gaps after doping. Gd-doped WOx coated on the ZnO/glass SAW device demonstrates the best performance in enhancement of UV sensitivity which is 14 times higher than the uncoated SAW device. The incorporation of dopants Gd into the WOx matrix leads to a multitude of effects that collectively enhance the UV sensing performance, including modified band gap, increased charge carrier generation, enhanced conductivity, efficient charge separation, and recombination suppression. Electrical properties and UV sensing mechanisms on ZnO/glass SAW devices based on Gd-doped WOx were studied, and the frequency shifts in these SAW devices are primarily due to ultraviolet-induced changes in conductivity and thermal effects.