Based on the investigation and monitoring of sedimentary environment, dynamic conditions and topography of the Nansha beach in Zhujiajian, the longshore sediment transport is calculated and analyzed by using different wave energy flow methods. The results show that the main type of beach sediments is sand, and the depositional substance is mostly from efflorescent rock. Affected by waves, tides, tidal currents and sedimentary environment, the seasonal variation of beach profile is obvious, which is the erosion in summer and the deposition in winter. The characteristic that is erosion in the east and deposition in the west is closely related to the coastal sediment transport. The calculation results of longshore sediment transports show that the net volume of sediment transport is between 43. 85×10³ m³/a and 172. 77×10³ m³/a. The direction of longshore sediment transport from east to west is mainly caused by ESE and SE incident waves, and the direction from south to north is caused by S incident waves. Without considering the impact of human activities on the beach, the longshore sediment transport plays a key role in the long-term evolution.