Abstract: Embankment frost heave and road collapse problems are caused by freezing in winter and melting in spring. Using lime,SH agent,polypropylene fiber,and basalt fiber stabilized soil,freeze-thaw effects on the compressive strength,elastic modulus,and microstructure of two types of SH agent-lime-fiber-soil were studied. The correlation between mechanical properties and microstructure parameters was analyzed,and the freeze-thaw durability of the two types of SH agent-lime-fiber-soil was evaluated. The results showed that the optimal contents of SH agent,polypropylene fiber,and basalt fiber were 1.5%,0.2%,and 0.2%,respectively. As freeze-thaw cycles increased,the compressive strength and elastic modulus of the two types of SH agent-lime-fiber-soil decreased; the particle area fraction and particle equivalent diameter decreased,while the particle aspect ratio increased. Microcracks in the soil gradually increased and extended into through-microcracks,leading to a looser soil structure. The correlation degrees between the compressive strength and elastic modulus of the two types of SH agent-lime-fiber-soil and the particle area fraction,equivalent diameter,and aspect ratio decreased in sequence. Fiber reinforcement mainly enhanced mechanical properties by increasing the area ratio. Compared with SH agent-lime-basalt fiber-soil,under the same freeze-thaw cycles,SH agent-lime-polypropylene fiber-soil has higher compressive strength and elastic modulus,and better freeze-thaw resistance. Adding 8% lime,1.5% SH agent,and 0.2% polypropylene fiber to the soil can improve its freeze-thaw durability and meet the filling requirements of embankment soil.