The present disclosure relates to the field of circuit testing technologies and discloses a flexible circuit board and a test fixture. The flexible circuit board comprises: a flexible body which has a first crimping portion and an extension portion, the first crimping portion being used to be laminated with a second crimping portion of a substrate to be tested; a first electrically connected structure which is located on a first side of the flexible body, arranged on the first crimping portion, and used to be laminated with a second electrically connected structure on the second crimping portion; a support structure which is located on the first side of the flexible body and includes a first support portion and a second support portion; the first support portion is arranged on the extension portion and configured to support the extension portion in the laminating state.