Aiming at the expansion of the first 300，000 DWT artificial channel in China，this paper expounds on the necessity of channel expansion from the aspects of navigation saturation，increasing trend of ship flow in core port area，upsizing of ships，and berthing demand，etc. Based on the analysis of the adaptability of extending the duration of tide and navigation capacity of the extended channel，the expansion scale and scheme of the channel are determined，and the effects of channel expansion，such as the improvement of flow conditions，sediment siltation，channel scale simulation，and the matching of the ships entering channel and berthing wharf time，are systematically studied. The proposed expansion scheme of deepening to -23.5 m and widening to 440 m is reasonable and has a good navigation effect，the expansion scheme can meet the navigation requirements of ships’ safe passing through the channel and berthing at one tide.