Plateau climate characteristics are prominent in Qinghai - Tibet plateau permafrost region,such as low annual average temperature,larger daily temperature difference,frequent and critical freeze-thaw cycles. These traffic impacts and environmental factors resulted in highway pavement appearing various distresses, structure capacity rapid deterioration,lifecycle sharply shorten,pavement performance and serviceability attenuation. Nearly 60 years temperature and precipitation meteorological data in Wudaoliang area along the Qinghai - Tibet highway are statistical analysed,the freeze-thaw intensity classification criterion in real environment based on the freezing and thawing temperature is proposed. Nearly 60 years monthly freeze-thaw cycles and the variation trend are analyzed. Mann - Kendall test method,Morlet wavelet analysis method, and R /S analysis method are used to analyze the freeze-thaw variation trend of Wudaoliang area in real environment. The research result shows that (1) the freeze-thaw effect in Wudaoliang area is mainly concentrated in March to June and September to October,the annual variation of freeze-thaw is fluctuated, and the whole trend presents decline from the 1990s; (2) the variation trends of annual and monthly freezethaw changes are verified using M - K test method,the annual freeze-thaw cycles presents decline with time, while the monthly freeze-thaw cycles is complex due to the environment impact; (3) according to the wavelet analysis,the 1st,2nd and 3rd main periods of obvious freeze-thaw variation trends in Wudaoliang area are 25 - 27,13 - 15,5 - 7 years respectively; (4) by R /S analysis,the future freeze-thaw variation in Wudaoliang area shows random trend; (5) although the freeze-thaw cycles of Wudaoliang area shows decreasing with time,while the amount of freeze-thaw cycles is large,the freeze-thaw effect is still the main influencing factor of highway engineering in the Qinghai - Tibet plateau permafrost region.