The invention discloses an efficient cultivation 
system and method for mudflat economic 
shellfish juvenile mollusks. A 5-8 mu 
algae species pond and a 20+ / -2 mu 
algae enlarged culture pond is constructed, 
seawater and 
algae species therein are introduced, and algal 
facies of the 
seawater in the algae species pond is observed, thereby facilitating disinfection treatment and fertilization of the 
seawater in the pond. After microscopically detecting the algal 
facies, proper algal 
facies are selected, directional enlarged culture on high-quality algae is conducted, water is fertilized to quickly 
breed the algae to a certain scale, 1 / 3 of seawater reaching the specified enlarged culture concentration in the algae species pond is introduced into the enlarged culture pond for enlarged culture, water is added again to reach the enlarged culture density, pond moving operation is repeated for continuous culture, and finally, water in the enlarged culture pond is led into a 
seedling raising chamber for 
juvenile mollusk running 
water circulation feeding culture, so as to promote growth and development of 
shellfish. According to the method disclosed by the invention, about 10 billion seedlings with the specification of 1,600,000 / kg can be cultured in the 
seedling raising chamber with the culture scale of 4-5,000 square meters, so that the culture cost is saved.