In view of the problems such as lack of mechanized harvesting equipment, high labor intensity, low efficiency and muddy working environment in the coastal shellfish aquaculture industry in Bohai Rim, a crawler type beach-shellfish harvesting machine is designed. The hydraulic power is distributed by hydraulic double pump, and the hydraulic power system is simulated by hydraulic system simulation software AMESim. According to the biological characteristics, geological characteristics and operational requirements of the mudflat shellfish cultivation, the design of the excavation and transmission device, the use of fixed excavating shovel and vibrating screen for shellfish sediment mixture excavation and screening, through the expansion of the hydraulic cylinder to adjust the depth of the harvester operation; Based on the distribution of each mechanism and hydraulic components, the crawler chassis is designed. Through the field test, complete the prototype performance test. The results show that the optimal process parameters of the harvester in the test area are 0.15 m/s, 380 r/min and 12° dip Angle of the vibrating screen, which can meet the agronomic requirements of the beach shellfish anhydrous and shallow water mechanized harvesting. The research shows that the crawler shellfish harvester has good stability, and has remarkable effect in improving work efficiency and reducing labor intensity, so it has the prospect of popularization and application.