The invention discloses a single-channel-to-multichannel switching device of a poultry-egg processing and conveying line. The single-channel-to-multichannel switching device comprises a single-channel conveying line, a multichannel conveying line, a movable channel dividing device and a fixed channel dividing device. The single-channel-to-multichannel switching device is connected with an existing poultry-egg single-channel washing and conveying line and a multichannel detecting, grading and conveying line; under the common effect of the movable channel dividing device and the fixed channel dividing device, the time for which poultry eggs at different positions are pushed by movable combs is different, the poultry eggs are sequentially distributed to the different fixed combs, and are sequentially switched to the multiple part from the single channel accordingly, extrusion and collision among the poultry eggs are prevented when channels are switched, and breakage is reduced.