A pre-mixed strontium silicate-based hydraulic cementing paste composition, a preparation method therefor, and an application thereof. The pre-mixed strontium silicate-based hydraulic cementing paste takes strontium silicate as a main phase, is prepared from at least one non-aqueous solvent which can be miscible with water, and further comprises at least one calcium phosphate compound and at least one radiopaque material, so that the biological hydraulic cementing paste having an excellent injectable property is prepared. The strontium silicate-based hydraulic cementing paste maintains fluid under a sealing condition and carries out hydration solidification hardening after being in contact with a physiological body fluid. A strontium silicate-based material has excellent biocompatibility and bioactivity, and the prepared pre-mixed strontium silicate-based cementing paste can be used for medicine and dental dentistry, comprising pulp capping, root canal therapy, dental repair and the like.