The invention discloses a mechanical transmission safety protection device for an electric suction apparatus. The mechanical transmission safety protection device comprises an electric suction apparatus main body, a first storage bottle, a second storage bottle and a floater power cutoff device, wherein the electric suction apparatus main body mainly comprises a vacuum pump and an electric suction apparatus main switch. The mechanical transmission safety protection device is characterized in that: the first storage bottle and the second storage bottle are arranged on a platform at the front end of the electric suction apparatus main body; a first silicone tube is connected to the first storage bottle; the first storage bottle is connected with the second storage bottle through a second silicone tube; the second storage bottle is connected with a vacuum pump of the electric suction apparatus main body through a third silicone tube; and the floater power cutoff device is arranged on a bottle cap of the second storage bottle, and is used for controlling the electric suction apparatus main switch to control power supply for the vacuum pump through a lead. The mechanical transmission safety protection device has the beneficial effects of small external influences, avoidance of influences of factors such as blockage, loss and the like, and high sensitivity, and is particularly suitable for sucking a large quantity of liquids during rescuing of patients and surgical treatment.