High frequency force balance test was conducted on triangular lattice mast and the along-wind, across-wind and torsional wind load spectra and mean force coefficients were obtained. The mathematical model based on the wind velocity function was used for the curve fitting of the along-wind load spectra and the applicability of the empirical formula in different flow fields was verified. Mathematical model consisted of turbulence and wake excitation was established for the across-wind load and torsional wind load according to the characteristics of the test spectra. Fitting results of least square method showed that the mathematical models were in good agreement with the test results. The contribution of turbulence excitation was dominant in across-wind load and the proportion of wake excitation was only 10% when the turbulent intensity was 15%. In torsional wind load the contribution of wake excitation increased obviously and accounted for about 40%.