The present invention provides a carbon nano-tube three-dimensional fin-like field effect transistor and a preparation method therefor. According to the method, carbon nano-tube parallel array materials are self-assembled on a three-dimensional fin-like insulated substrate surface, so that the number of carbon nano-tubes on the width of a unit device is effectively increased, and thus the drive current of a carbon nano-tube transistor device is significantly increased. Compared with a conventional plane carbon nano-tube device, the carbon nano-tube three-dimensional fin-like field effect transistor has significant advantages in the aspects of driving capability, performance uniformity and integration degree.