The present invention discloses a reverse-flow-free 
nanofiltration apparatus or a reverse-flow-free 
reverse osmosis apparatus, and in particular relates to a shutdown reverse-flow-free 
nanofiltration apparatus or a shutdown reverse-flow-free 
reverse osmosis apparatus. The shutdown reverse-flow-free 
nanofiltration apparatus or the shutdown reverse-flow-free 
reverse osmosis apparatus includes an adjusting tank and a filter film unit which is connected with the adjusting tank, the filter film unit is provided with a water inlet and two water outlets, the two water outlets are respectively connected with a production water tank and a concentration water tank, the concentration water tank and the production water tank are respectively provided with 
water discharge ports, the production water tank is provided with two 
water discharge ports, and one of the 
water discharge ports is connected with the water inlet of the filter film unit. When in shutdown work, water in the production water tank is led into the water inlet of the filter film unit by a 
pipe to replace water in the adjusting tank for sustained input, the phenomenon of reverse flow, which is caused by internal high 
osmotic pressure due to sudden shutdown of a high-pressure pump, of production water of a film to a concentration water side can be effectively avoided, filtrationfilm 
surface wrinkling and damage can be avoided, filtrationfilm 
desalination performance and 
system stability can be ensured, and the service life of the reverse-flow-free nanofiltration apparatus or the reverse-flow-free reverse 
osmosis apparatus can be prolonged.