The invention discloses a device and a method for measuring the flow rate of steel melt near the surface thereof, wherein the device comprises a flow rate detecting rod (18) and a deflection means (B) for the flow rate detecting rod. The deflection device (B) for the flow rate detecting rod comprises a flow rate detecting rod counterweight (20), a deflection bearing sleeve (23), a deflection bearing (24), a deflection angle indicating board (25), a deflection angle pointer (26) and a the flow rate detecting rod fastening bolt (27). Both the deflection bearing sleeve (23) and the deflection bearing (24) are circular parts, and the deflection bearing (24) is slidably set against the inner wall of the deflection bearing sleeve (23). The outer surface of the deflection bearing sleeve (23) comprises a counterweight rod extending outward. The counterweight rod and the flow rate detecting rod fastening bolt (27) are respectively fixed to the outer surface of the deflection bearing sleeve (23). The flow rate detecting rod counterweight (20) is fixed on the counterweight rod. The method comprises the following steps of calculating the distance between the rotational pivot and the barycenter, as well as the distance between the rotational pivot and the acting point of the impact force based on the barycenter, a rotational pivot and an acting point of an impact force of a flow rate detecting rod (18); measuring the gravity value of the flow rate detecting rod (18); inserting the flow rate detecting rod (18) into the steel melt to measure the rotational angle and insertion depth; and thereby calculating the flow rate of the steel melt.