Non-explosive expansion materials (NEEMs) are eco-friendly demolition materials widely used in energy extraction. However, their low hydration efficiency restricts their further application. To address this issue, five NEEM samples with different anhydrous CaCl2 concentrations (0, 0.4, 0.8, 1.2, and 1.6 %) were prepared. The water distribution, mineral composition, and microstructure of the samples during hydration were investigated using NMR, XRD, FTIR, and SEM, respectively, and the enhancement mechanism caused by CaCl2 on NEEM hydration was revealed. Results showed that CaCl2 inhibits the transport of surface water to large pores and cracks; promotes the combination of CaO, C3S and free water; accelerates the transformation of surface water to gel water and capillary water; shortens the dormancy period; and promotes the formation of hydration products. It also accelerates the flocculation of C-S-H gel and the transport of capillary water, thereby significantly improving the NEEM hydration efficiency. The established hydration kinetics model showed that the transport rate of surface water and capillary water to gel water and the NEEM hydration degree increase with increasing CaCl2 content. Compared with the hydration degree of R1 (0 %), that of S4 (1.6 %) increases by 19.63 %. These results provide a theoretical foundation for the field application of NEEMs.