In response to the galloping issue faced by ice-covered multi-split transmission lines， this study proposes a method based on the probability density evolution approach for dynamic tension stochastic analysis and reliability evaluation of such transmission lines. A stochastic analysis method for the dynamic tension in ice-covered multi-split transmission lines is established by integrating the finite element model with the probability density evolution technique. A tensile failure criterion for ice-covered multi-split trans? mission lines is developed by using the equivalent extreme value distribution method， and a framework for reliability evaluation of the transmission lines is constructed. Stochastic dynamic response analysis and reliability evaluation on a single-span ice-covered four-split transmission line are conducted. The analysis of the example shows that： The method in this paper can efficiently analyze the stochastic dynamic tension of the ice-covered four-split transmission line， and the stochastic dynamic tension is influenced by multiple modes after the transmission line enters the stable galloping stage； The tensile failure reliability probability of transmission lines during galloping does not exhibit a monotonous relationship with the increase of initial sag； The initial wind attack angle plays a crucial role in determining the tensile failure reliability probability of the transmission line， and the reliability of the transmission line is relatively low when the initial wind attack angle falls within the range of 20° to 60°.