It is important to consider low temperature brittle failure in fatigue design, in order to investigate the crack propagation behavior of X80 pipeline steel in cold environment, charpy impact toughness test, fatigue crack propagation rate (da /dN) test and fatigue crack propagation threshold test of 10mm thick X80 steel were carried out at room temperature and low temperature.The results show that the charpy impact energy and the shear section ratio decrease with the decrease of temperature.Under the stress ratios of 0.1, 0.5 and 0.8, the fatigue crack growth rate slows down with decreasing temperature, and the fatigue toughen-brittle transition temperature of X80 steel is below 60°C.At room temperature ~60°C, the crack growth rate is insensitive to the change of stress ratio.When the stress ratio is 0.1, the threshold value of fatigue crack growth tends to increase slightly with the decrease of temperature. The experimental data can provide reference for the subsequent research.