The invention discloses an environment-friendly type underwater non-dispersible sludge curing agent for ecological restoration. The environment-friendly type underwater non-dispersible sludge curing agent is prepared from the following raw materials in parts by weight: 5 to 30 parts of clinker, 2 to 8 parts of a waterproof agent, 2 to 5 parts of bentonite, 2 to 5 parts of lime, 5 to 8 parts of gypsum, 0.04 to 1 part of a water dispersion resisting agent and 0.5 to 5 parts of an exciting agent, wherein the clinker is a mixture of silicate and aluminate. The product can be used for hardening various sludge in water and improving an aggregate structure of the sludge and can be used for sealing toxic and harmful substances including heavy metal ions, cyanide, fluoride and the like; production and preparation and application processes of the product does not cause toxin and pollution and environmental hazards are not caused; the sludge treated by the product has the characteristics of relatively good whole water dispersion resisting performance and water flow scouring resisting performance, a rapid hardening speed, no need of special curing and the like; plants can grow on the sludge and caves for inhabitation can be built on the sludge, so that an ecological diversity function is met; the restoration of the ecological environment is facilitated and the utilization effect is good.