The invention discloses a blocking layer modulation structure-based current aperture power transistor and a fabrication method thereof, which are used for mainly solving the problems of low breakdown voltage and large conduction resistance of an existing device. The current aperture power transistor comprises a substrate (1), a drift layer (2), a current aperture layer (3), left and right symmetric multi-stage step structure current blocking layers (4), a channel layer (6), a barrier layer (7) and a passivation layer (12), wherein two sources (9) are deposited at two sides of the barrier layer (7), two injection regions (8) are formed below the two sources (9) by ion injection, a grid (10) is deposited on the barrier layer (7) between the two sources (9), a drain (11) is deposited on a lower surface of the substrate (1), the passivation layer (12) completely wraps other regions except a bottom part of the drain, and an aperture (5) is formed between the two symmetric current blocking layers (4). The current aperture power transistor has the advantages of high breakdown voltage, simple process, small conduction resistance and high finished rate, and can be used for a power electronic system.