Parabolic trough collector (PTC) is a mature concentrating solar power technology that has been commercialized for the recent decades. However, in the operation experience, it is found that the wind load introduces a considerable threat on its performance and safe operation. In this paper, the deformation, vibration and corresponding optical efficiency loss (optical efficiency difference between non-wind and wind conditions) of parabolic trough collectors induced by wind load are systematically studied. A three-dimensional multiphysics-coupled (fluid dynamics-elastic mechanics-geometrical optics) transient model is firstly established in COMSOL Multiphysics and validated by benchmark data. Then, the wind load effects are investigated and the following conclusions have been drawn: (1) The maximum displacement increases with the increase of wind speed and quadratic fitting curve exhibits better agreement compared with exponential curve used in previous study. When wind speed is 14 m s(-1), the maximum displacement reaches 9.55 mm and the corresponding optical efficiency loss is 19.83%. (2) Pitch angle significantly affects flow fields and deformations. When the pitch angle varies from 0 degrees to 270 degrees, the maximum deformation and minimum deformation are obtained at theta = 0 degrees and theta = 270 degrees, respectively. Besides, more precise flow fields with more details have been obtained compared with early studies. (3) By comparative investigation, it is proved that replacing time-varying wind speed with mean speed is inaccurate, which may underestimate the practical deformation and optical efficiency loss. (4) By elastic investigation, it is proved that aeroelastic response could occur locally while self-excited vibrations are not likely to occur under most practical operation conditions.