The invention relates to a low-loss dry-type transformer. The transformer comprises iron cores, coils, clamping parts and the like, the coils comprise low-voltage coils and high-voltage coils, the iron cores are composed of upper iron yokes, lower iron yokes, upper clamping parts, lower clamping parts, lateral threaded rods and pull plates, the pull plates are iron core pull plate bodies made of steel, and holes are formed in the iron core pull plate bodies; the transformer further comprises an outer ventilation dustproof cover body, the cover body is divided into a top plate, a middle part and a baseplate, and multiple wind inlet windows are formed in the middle part of the cover body; multi-layer filter screen structures are arranged on the wind inlet windows, and automatic dust shakingmechanisms are arranged on the multi-layer filter screen structures. The low-loss dry-type transformer has the advantages that loss of the transformer is lowered, the ventilation and dustproof performance of the transformer is improved, and energy saving is effectively promoted.