The utility model relates to a safety device for strong acid dilution. The device comprises a liquid containing bottle and a speed control pipe, a liquid outlet and a speed control pipe connected withthe liquid outlet are arranged at the bottom of the liquid containing bottle; a control valve is arranged on the speed control pipe; the device further comprises a diluting device and a cooling device, the diluting device comprises a cylindrical diluting cup; a base is further included, fixing rod on base, a circular hole is formed in the fixed rod; the left end of a rotating shaft on the fixed rod penetrates through the circular hole; rotating disc is welded to the base, a bevel gear I is arranged at the right end of the rotating shaft, a horizontal rod is connected to the upper end of the fixing rod, a bearing seat is connected to the right end of the horizontal rod, a stirring shaft is connected to the bottom of the bearing seat, a bevel gear II is connected to the upper portion of thestirring shaft and meshed with the bevel gear I, and rotating blades are fixed to the lower end of the stirring shaft. In the strong acid dilution process, the temperature of the system is kept at anormal level, and liquid splashing caused by sudden temperature rise of the system is prevented from hurting human bodies and the like.