Embodiments of the present disclosure provide an oxide thin film transistor and a manufacturing method therefor, and an electronic device. The oxide thin film transistor comprises a base substrate (21), a gate (22) and a metal oxide semiconductor layer (24) that are sequentially stacked on the base substrate (21), and a gate insulating layer (23) provided between the metal oxide semiconductor layer (24) and the gate (22), wherein the gate insulating layer (23) comprises a silicon oxide insulating layer (231) and a silicon nitride layer (232) that are stacked; the silicon nitride layer (232) is of a single-layer structure or comprises a plurality of silicon nitride sub layers that are sequentially stacked; the silicon oxide insulating layer (231) is provided between the silicon nitride layer (232) and the metal oxide semiconductor layer (24); and at least part of the region of the silicon nitride layer (232) satisfies that: an Si-H bond occupies an Si-N bond, and the percentage content of the sum of an N-H bond and the Si-H bond is not greater than 7%. The thin film transistor can solve the problem of bulging of the gate insulating layer by adjusting the structure of the gate insulating layer.