Disclosed is a fluid diverting device which comprises a saddle unit, a water dividing unit and a leakproof tube unit. The saddle unit includes a saddle body, a water inlet through hole and a main pipe accommodating portion. The water dividing unit includes a water dividing main portion, an inlet tube portion and an outlet tube portion. The inlet tube portion is inserted into the water inlet through hole. A screw thread is provided on an external tube wall of the inlet tube portion or on an internal tube wall of the inlet tube portion. The leakproof tube unit includes a sleeve portion, a connecting portion and a leakproof pad. The connecting portion is provided on one end of the sleeve portion and the leakproof pad is in tight contact with the connecting portion. A corresponding screw thread is provided on an external tube wall of the sleeve portion or on an internal tube wall of the sleeve portion. The sleeve portion is screwed with the inlet tube portion in a manner that the external tube wall of the sleeve portion is screwed with the internal tube wall of the inlet tube portion or the internal tube wall of the sleeve portion is screwed with the external tube wall of the inlet tube portion.