The invention relates to a manufacturing method for a flexible semiconductor device, comprising the following steps: providing a hard substrate which is provided with a surface; providing a flexible substrate which is provided with a first surface and a second surface arranged opposite to the first surface, and fixing the first surface of the flexible substrate on the surface of the hard substrate; adopting a semiconductor processing technology to directly form a semiconductor device on the second surface of the flexible substrate; and removing the hard substrate to form the flexible semiconductor device. By adopting the manufacturing method, while semiconductor processing is directly carried out on the flexible substrate so as to form the flexible semiconductor device, the phenomena of flexible substrate curling and surface relief can be avoided, thus the processing can be conveniently carried out and the precision of the flexible semiconductor device can be improved.