The plastic deformation as a main form of failure of Interference Joints may happen in engineering works if it is designed unreasonably. In this paper, the contact stress and the strength of Interference Joint parts were analyzed deeply. Based on the theory of the reliability design, the general formulas and the method of the reliability design and computation for Interference Joint were established in consideration of joint structure, machining precision, interference value, mechanical properties of the joint parts and their randomicity. The practical design method, which would promote the reliability of Interference Joint effectively, was proposed for larger size and some other important Interference Joints. Compared to the conventional design method, the working reliability of Interference Joints can be improved obviously by means of the reliability design method.