A method and a device for controlling a capacity change of a compressor, and a smart home appliance. The method includes: determining whether a capacity of the compressor is required to be changed; if yes, determining an intermediate frequency; changing the capacity of the compressor while maintaining the operating frequency of the compressor at the intermediate frequency; and the maintaining the operating frequency of the compressor at the intermediate frequency reduces a sudden change in output of the compressor after the changing the capacity.