The effects of different inorganic salt accelerators (CaBr₂, NaBr, Ca(NO₃)₂, NaNO₃) and an alkali-free liquid accelerator were researched at a low temperature of 10 °C. The results showed the effects of 1.5% NaBr and 1.5% NaNO₃ inorganic accelerator were pronounced. The 1-d compressive strengths of the mortar with these two inorganic salts were increased by 185.8% and 184.2%, respectively, and the final setting times were shortened from 7.74 to 6.08 min and 6.12 min, respectively. The hydration temperatures at 10 °C were measured, and the promotion effects of the inorganic accelerators were calculated: the relationship between the hydration degree was α_{AS + NN} > α_{AS + NB} > α_{AS + CB} > α_{AS + CN} > α_AS. In addition, the reaction of C₃A with NaBr and NaNO₃ was used to analyze the products in an ettringite phase, i.e., Ca₄Al₂O₆Br₂10·H₂O, 3CaOAl₂O₃Ca(NO₃)₂X·H₂O. The formation of these phases was detected in the hydration products of the cement paste hydration for 12 h, 24 h, and 28 d. Combined with the mass loss of the ettringite phase at 90–120 °C, determined using TG/DTG, the synergetic acceleration mechanism of the inorganic accelerators was comprehensively inferred.