The invention discloses a method for determining the shape of a semi-floating supporting bearing inner bore oil wedge of a supercharger. The method is characterized by comprising the following steps: drawing two concentric circles which are concentric with an axle with the radius of Rb and R2 according to the limited conditions of the value of a1 and b, and axle radius Rs, the base radius of the bearing inner bore (Rb=Rs+b), and the axis distance (R2=Rs+a1) of the deepest point distance axle manufactured on the inner wall of the supporting bearing; dividing the two concentric circles into n equal parts according to the number n of oil wedges; and connecting 2n along ents sequentially by virtue of a curve, wherein the polar equation of the curve is rho=Rm+e*sin(n*t) or rho=Rm+e*cos(n*t), and the curve is in the shape of the supporting bearing inner bore oil wedges. According to the invention, a more simple method is used for designing and describing the oil wedges of the bearing inner wall, not only can the limiting requirement of the bearing design be satisfied, but also the design and drawing difficulty is reduced, the drawing label is simplified, the manufacturing difficulty is reduced, and the consistency of the appearance of the product is ensured.