The invention provides an integral blade disc and a manufacturing method thereof. The manufacturing method comprises the steps of (1) allocating and fixing all blades along the circumferential direction of a disc type piece; (2) carrying out linear friction welding on all the blades and the disc type piece along the circumferential direction of the disc type piece; simultaneously applying an upsetting force along the axial direction of the disc type piece to keep the contact between the blades and the disc type piece; (3) enlarging the upsetting force along the axial direction of the disc type piece to fixedly connect the blades and the disc type piece when the temperature on the contact surfaces between the blades and the disc type piece is heated up to metal plastic deformation temperature, and obtaining preformed blank of the integral blade disc; (4) carrying out after-treatment on the preformed blank obtained in step (3), and obtaining the integral blade disc. According to the manufacturing method disclosed by the invention, when the blades are welded on a blade disc, the blades and the blade disc do high-speed reciprocating motion along the circumferential direction, so that the mutual position accuracy between the blades cannot be affected no matter where the blades stop when the welding is ended, the requirements on equipment and technology are greatly reduced, and the rate of finished products is increased.