The freezing and thawing, shrinkage and expansion, and damage of tailings sand can cause great harm to the project of tailing dam in cold regions. In order to explore the deformation characteristics of tailing dam and reveal its deformation mechanism under freeze-thawing, down-scale tailings dam model tests were carried out on a self-designed device under different freezing temperatures (-5, -25, -45℃). The soil pressure, displacement and pore water pressure at each key position of tailing dam during the freeze-thaw cycle were measured by the dynamic data acquisition instrument. The test results show that:the internal stress of the dam increases with decrease of freezing temperature; the stress growth rate in the early stage of freeze-thaw cycleat each key position is higher than that at the other stages. The pore water pressure in the dam decreases with decrease of freezing temperature. The variation range, periodicity and regularity of pore pressure increases with the position depth of the dam. Besides, it is revealed that the freezing temperature has obvious position effect. The closer to the tailings dam edge, the greater the deformation magnifude of dam body and the higher of the deformation rate.