The utility model discloses a cable insulation explosion -proof box with survey mouth, including cylindric explosion -proof box casing, the casing includes the casing, descends the casing, the last casing mid portion of explosion -proof box is equipped with one and observes the mouth, survey a mouthful upper end be stained with visual glass with the insulating seal adhesive tape, the casing both ends are constriction portion, and seal the casing with the sealed with silicone rubber circle constriction portion outside, and internal diameter thickening sealed insulation pad is posted to inside, there is the hem casing side along the axial, and the hem inside of upper and lower casing combines with the insulating seal adhesive tape, have the screw on the hem, the use is consolidated the buckle fast and is sealed. A foretell cable insulation explosion -proof box with survey mouth, it accomplishes fire -retardant explosion -proof reducing the loss when cable joint goes wrong, be convenient for survey when the maintenance repair problem, taking precautions againt calamity simultaneously.