Abstract: Frost heaving disaster is a common problem in the construction engineering of seasonal frozen soil area. In order to study the frost heaving characteristics of coarse sandy soil in Mohe section of Heilongjiang River, the flood plain coarse sandy soil in the basin was taken and the temperature control mode specified in the test specification and the unilateral freezing mode with side limit were adopted to carry out the frost heaving test on coarse sandy soil with different moisture contents and dry densities. The results showed that the freezing process of coarse sand was divided into the following four stages: supercooling stage, abrupt temperature change stage, pore water crystallization stage and stable freezing stage, and the initial freezing temperature of coarse sandy soil was-0.19 ℃. In the process of freezing, the development law of temperature field and temperature gradient in coarse sand samples with time was studied. The freeze-heaving rate of coarse sandy soil in Mohe section of Heilongjiang River was less than 1% under all the test conditions. Within the test range,the frost heaving rate of coarse sandy soil increased with the increase of sample moisture content, and with the increase of sample dry density, the frost heaving rate of coarse sandy soil had a linear relationship with dry density and water content.