The invention discloses an endogenous toughened corrosion-resistant cement mortar system which is composed of the following components in parts by weight: 100 parts of high-sulfate-resistance Grade-G oil well cement, 5-35 parts of microcrystal calcium aluminoferrite, 0-25 parts of micro silicon, 1.0-4.5 parts of water-loss control agent, 0.5-3.0 parts of dispersing agent, 0.2-3.0 parts of thickening time control agent and 44-80 parts of water. The microcrystal calcium aluminoferrite is prepared by high-temperature calcination and shock cooling. The micro silicon is a density regulator. The water-loss control agent is polyvinyl alcohol, polyacrylamide or carboxymethyl cellulose. The dispersing agent is sodium hexametaphosphate, melamine formaldehyde resin, sodium lignosulfonate or methyl cellulose. The thickening time control agent is boric acid, gypsum, sodium borate or a mixture thereof. The endogenous toughened corrosion-resistant cement mortar system has the advantages of excellent impact resistance, higher compression strength, high volume stability and small changes of porosity and permeability, has important meanings for ensuring safe and efficient development of shale gas, and thus, has broad market prospects.