Disclosed are a variable-capacity control structure, a compressor and a variable-capacity control method thereof. The variable-capacity control structure includes: a variable-capacity assembly and a sliding vane restraint unit; the variable-capacity assembly is provided outside a housing of a compressor to which the variable-capacity control structure is attached, and is configured to act in a setting order; the sliding vane restraint unit is provided inside a pump body of the compressor, and is configured to cause a variable-capacity cylinder assembly in the compressor to be in a working state or an idling state under controlling the variable-capacity assembly to act in the setting order. By the solution of the present disclosure, advantages that vibration is reduced, compressor is not easy to shut down and pipeline is not easy to break are implemented.