The invention discloses a gel material used for unclassified tailing cement, which comprises the following raw materials by weight ratio: 15.5%-17.5% of desulfurized gypsum, 3.5-5.5% of high calcium lime and 77%-81% of water quenching slag powder. According to the invention, desulfurized gypsum, high calcium lime and an additive are taken as a main material for preparing an high efficiency exciting agent, the high efficiency exciting agent can excite the water quenching slag powder having latent activity, thereby a gelling effect is generated, hardening is generated under the hydration effect, and the material can form a high-strength filling body. The exciting agent material of the gel material is desulfurized gypsum wasted by a power plant, the source of the material is wide, the price is low, no secondary processing is required, therefore the cost is low. The exciting agent and the water quenching slag powder are mixed to form the gel material; the water quenching slag is the ironmaking waste, and has the characteristics of wide source, low cost and easy being grinded. The gel material is suitable for 20-30% of -20mum fine sludge -containing filling material, the obtained filling mortar has good fluidity, and the strength of the filling body is high.