## 1 Introduction
This method can obviously compress the data storage and accurately describe the essential characteristics of the wind pressure field with fewer items [18; 19; 20; 21]. As early as 1967, [PERSON] introduced the POD method to the study of turbulence. Then the following year, [PERSON] [22] took the lead in introducing the POD method to the field of wind engineering. After that, many scholars in the field adopted this method to describe the fluctuating wind pressure field of the architectural structure. [PERSON] [23] pointed out that because the shape of eigenvectors is restricted by the requirement of orthogonality, the interpretation of its physical meaning may be distorted. However, he also pointed out that the fluctuating wind pressure field can be simplified into several modes for analysis by POD method. [PERSON] [24] applied the POD method to the research of wind speed field and wind pressure field and proposed a method that can simplify the description of wind load. [PERSON] et al. [25; 26] reconstructed the fluctuating wind field of a flat roof. [PERSON] [27] uses the POD method to describe the characteristics of wind pressure field in low-rise buildings. [PERSON] [28] adopted a database strategy and used POD technology to predict the wind pressure field in the far distance by interpolation based on the wind pressure field in the corner of the roof and compared the interpolation results with the measured data in terms of statistical characteristics and power spectral density. In recent years, [PERSON] et al. and many other scholars [29; 30; 31; 32] have expounded the application of POD technology in the reconstruction of wind pressure fields such as curved roofs and double-slope roofs. Since then, POD has gained more attention and application as an effective tool that can accurately and simplify the description of the wind pressure field [18; 19; 33]. However, there has been no research on the reconstruction of wind pressure field for folded-plate large-span roof structures based on POD technology. Therefore, it is necessary to further explore the applicability and accuracy of the POD method and different spatial interpolation methods in the reconstruction and prediction of the wind pressure field of the folded-plate large-span roof structure. The structures with this type often have typical roof surfaces such as windward and leeward folded plates, side folded plates, and roof planes, which are representative to a certain extent. With this type of structure, the wind loads in different wind-receiving areas of large-span roof structures can be systematically analyzed. This paper will take a high-speed railway station with a folded-plate large-span roof as the engineering background. First, the rigid model pressure measurement of the structure is carried out through the wind tunnel test to obtain the wind pressure time series of the measuring points on the roof surface, and the parameters such as the mean wind pressure coefficient and the body shape coefficient are analyzed. Then, based on the POD method, the wind pressure field of the roof is reconstructed by using the first several eigenmodes of the structure, and it is compared with the wind tunnel test results in terms of statistical characteristics, power spectrum, coherence function, etc., to study the applicability and effectiveness of the POD method in the reconstruction of the random wind pressure field of the folded-plate roof. Finally, the POD method is used to predict the wind pressure of some unknown measuring points of the structure based on various interpolation methods, and the accuracy and difference of different interpolation methods in the wind pressure prediction of the large-span roof structure are compared and analyzed.