Flexible supporting device for thin-wall part machining and self-adaptive supporting method

The invention provides a flexible supporting device for machining a thin-wall part, and relates to the technical field of mechanical engineering. The flexible supporting device comprises a displacement output unit and an online measurement and cooperative control unit; the displacement output unit comprises a driver, a displacement amplification mechanism and a contact; the on-line measurement and cooperative control unit is used for monitoring deformation, caused by supporting counterforce, of a first force transmission part on the displacement amplification mechanism in real time and monitoring a flutter signal of a to-be-supported part on the part in real time; the online measurement and cooperative control unit is further used for measuring and calculating the deformation compensation supporting amount of the to-be-supported part and controlling the driver to output displacement according to the deformation compensation supporting amount till the to-be-supported part recovers to the original shape. The on