Aimed at the situation that enclosure diversion can change the water flow field affect the drifting and aggregation of algae, this paper explored the enrichment efficiency of algae under different enclosure diversion plans through changing the angle and length of enclosure layout. Taking Pengkeng bay within Meiliang bay fishing area as the research object, the paper built the network model based on the coupled water quantity-quality model of Taihu lake.It simulated the enrichment efficiency under six different layouts according to the two factors of angle and length ,and got the best combined scheme. Furthermore,considering the terrain and economic benefits of Pengkeng Bay, it put forward optimum proposal that suits for the local terrain features. Results show that the enrichment efficiency is the best when the angle between enclosure layout and water flow is 120 degrees; the longer the enclosure is, the larger the collecting zone of blue-green algae gets, the better the enrichment efficiency becomes; the best plan is to set up a section of enclosure respectively in the upside and downside bay in comprehensively considering the terrain features and economic benefits, the angle between enclosure and water direation should be 120 degrees, and the length of upside and downside bay is 100 and 30 meters respectively. The result has a good application prospect for the improvement of water environment in Taihu lake.