Desert regions provide abundant solar irradiance and are thus attractive locations for utility-scale solar thermal plants; however, wind-driven dust loads generated by intense sandstorms pose a serious hazard to the safe operation of parabolic trough collectors (PTCs). Accordingly, investigating dust-mitigation design for PTCs under sandstorm conditions is essential. This study employs numerical simulation to assess how variations in installation tilt, wind-direction orientation, incoming wind speed, and dust volume fraction influence vortex characteristics and wind-dust pressure distributions around PTCs. The results show that, across the examined range of installation tilts, the drag and lift coefficients associated with wind-dust loads are relatively large, while dust-induced moment components in the X and Y directions remain comparatively small. Under oblique wind conditions, asymmetric pressure fields and convex conical vortices amplify overturning moments, with mean dust moments in the X and Y directions approximately 27 and 3 times greater than those under vertical wind, respectively. Further analysis indicates that variations in incoming wind speed and dust volume fraction induce wind-dust load fluctuations of only about 1%-5%. Therefore, dust-mitigation measures for the reflectors should primarily target drag and lift. Anti-overturning design should concentrate on oblique wind scenarios within the 45 degrees-75 degrees range and account for abrupt moment changes induced by asymmetric vortices. This work provides a theoretical framework to inform dust-mitigation design criteria and overturning protection systems for PTCs deployed in desert solar thermal plants.