The main function of the Horizontal Tail (H-Tail) is to ensure the static longitudinal stability and the maneuver of an aircraft. The heavy take-off weight and the various CG of the Civil Aircraft make it highly demanded for the control ability of the H-Tail. To improve the efficiency of H-Tail,most Civil Aircrafts adopt deflectable HTails. With the deflection of both the H-Tail and the Elevator,together with the influence of the Wing and the Fuselage,the airstream around the H-Tail is quite complex and makes it difficult to calculate its aerodynamical load. This paper shows how to calculate both the total aerodynamical load and the distributional load of the H-Tail. It alsodemonstrates how to harmonize the total load based on the wind tunnel force tests and pressure tests,and shows some unique methods on how to modify the distributional load.