The causes of low temperature diseases of cement asphalt emulsified mortar (CA mortar) was analyzed. The influences of hardening process and filling quality of sulfur aluminum cement(SAC) and polymer latex on CA mortar in winter were studied, and the results showed that CA mortar is super retarding in low temperature, and the system stability deteriorated, then some diseases appeared such as bleeding, peeling by removing slab, et al. The SAC could accelerate the hardening process with the substitution amount of SAC increases, and the setting time of CA mortar is faster. With the increase of temperature, the stirrable time of latex-cement system showed a decreasing trend, and uniform and stable of fresh CA mortar could be improved by latex with suitable thickening performance in low temperature. The expansion rate and 24h compressive strength of CA mortar which combined admixture SAC(the content of 10%) and polymer latex(the content of 8%) met the standard requirements, in 0.5 ℃~7.7 ℃ environment, and CA mortar showed cross-section uniformity and smooth surface without peeling by removing track slab, which meet the requirement of the technology requirements.