The invention provides a linear friction welding device for manufacturing an integral impeller. The linear friction welding device comprises a base (1), and is characterized in that an upright post (2) provided with guide rails is arranged in the center of the base (1), an upper press plate (4) is arranged on the upright post (2) provided with the guide rails, an impeller disc (10) is arranged and clamped between an upper press plate (4) and a lower support plate (3), and the lower support plate (3) is connected with a hydraulic system (11) and can fast and vertically do reciprocating movement along the upright post (2) provided with the guide rails through being driven by the hydraulic system; on the base (1), guide rails (8), distributed in the radial direction, with the same number of the impellers are distributed and arranged around the upright post (2) provided with the guide rails along the circumference, and an installing and clamping device (7) used for installing and clamping blades (9) is arranged on the guide rails (8) and is connected with an impact compressor (5) which is also arranged on the guide rails (8) through a connecting rod (6). The linear friction welding device has the main advantages that the processing efficiency of the integral impeller disc is greatly improved, in addition, the performance consistency of a welding region is improved, and further, the performance of the integral impeller is integrally improved. The production cost of enterprises can be greatly reduced, and the enterprise benefits are improved.