A dual-cylinder two-stage variable capacity compressor is provided, including: a first cylinder, having an exhaust port connected to a first exhaust channel: a second cylinder, wherein the second cylinder is provided with a ventilating slider, and the ventilating slider is provided with a first gas transit channel and a second gas transit channel; wherein, when the ventilating slider is at a first connecting position, the first exhaust channel is connected to a suction channel in a second cylinder when the ventilating slider is at a second connecting position, the first exhaust channel is connected to a second exhaust channel. The compressor of the present disclosure can vary its own capacity, that is, the variation of the compressor's capacity can be realized by arranging a ventilating slider, which will meet the requirements of variation loads of the compressor in different seasons.