This paper presented the analysis results of the wind field characteristics and wind pressure of the roof on the basis of the measurement data of the roof obtained in an instrumented low-rise building, which sits in Wenzhou and was affected by the typhoon Fitow. The results reveal that, with the decrease of the average interval, the maximal average wind velocity increases; the turbulence intensity tends to decrease with an increasing average wind velocity. Furthermore, the average wind pressure at the edge of the building roof and ridge is negative with large fluctuation. The variation tendencies of wind velocity and wind pressure show the obvious correlation between the velocity in wind field and wind pressure on the roof. The correlation analysis between the wind field characteristics and wind pressure on the roof was then conducted within different time intervals. The analysis results show that the wind velocity and wind pressure are correlated well at an average interval of 5 minutes, which indicates that the average interval of 5 minutes can be reasonably used to calculate the wind load.