[Objective] The structural characteristics of the near-surface airflow field and wind-sand flow under the disturbance of photovoltaic (PV) arrays in the Tengger Desert were analysed to assess the effect of PV arrays in preventing winds and fixing sands, in order to provide theoretical support for both the management of wind-sand disasters in desert areas and the sustainable development of ecological environments. [Methods] The vertical distribution of wind speed, wind velocity flow field, and wind-sand flow structure of PV arrays (front edge of electric panels, back edge of electric panels, and midline between arrays) and control points were assessed in the field using gradient wind speed observation equipment, and the airflow field and sand transport characteristics at different locations inside and outside a power plant were compared and analysed. [Results] (1) The overall wind speed inside the power station decreased, the average wind speed between arrays and along the back edge of the electric panel increased with height, and the average wind speed along the front edge of the electric panel decreased and then increased with height. (2) ① For the grass square observation section, the wind speed at the wind outlet in front of the electric panel increased significantly, and the wind speed along the wind inlet behind the electric panel and below 100 cm of the centre line between arrays decreased; ② For the wind erosion pit observation section, the wind speed of PV panels below 150 cm decreased, and the wind speed pulsation between arrays varied significantly; ③ For the gravel observation section, the relative rate of change of the wind speed and the pattern of the wind flow field were stable, and the wind speed along the back edge of the electric panel above 150 cm increased. The wind speed increased in the section above 150 cm behind the electric plate. The average wind protection effect occurred in the order of gravel > grass squares. (3) The order for sand transport was as follows: front edge of the electric plate > back edge of the electric plate > midline between the arrays; the reference point of the mobile sand dune (upwind) was saturated with λ (a characteristic value of the wind-sand flow structure) at the front edge of the electric plate, and unsaturated at the back edge of both the electric plate and λ between the arrays. [Conclusion] Compared with the mobile sand dune, the PV array perturbed the wind velocity flow field pattern, the wind velocity pulsation and turbulence degree changed, sand transport decreased significantly, and a sand fixation benefit was evident.