Fault diagnosis method for high-speed heavy-load input stage under unbalanced samples

The invention discloses a fault diagnosis method for a high-speed heavy-load input stage under unbalanced samples, which comprises the following steps of: monitoring a vibration signal by utilizing different simulated fault modes of a low-speed gear box experimental platform to obtain low-speed fault frequency spectrum data, and obtaining fault frequency spectrum data of a high-speed gear box experimental platform under different fault modes through transferring of frequency spectrum; transferring the fault frequency spectrum data of the high-speed gear box experimental platform to a fault mode of an input stage gear box of a helicopter to obtain the fault frequency spectrum data of the input stage of the different fault modes; carrying out pre-training on a deep stack denoising automaticencoder SDAE by utilizing the fault frequency spectrum data of the input stage obtained by double transferring and the frequency spectrum data of the vibration signal monitored under an actual operation state in a normal mode