The invention discloses an automatic testing system and method of router USB performance. The testing method includes the following steps that (101), functions of a router USB are configured; (102), external storage equipment is configured; (103), batch scripts capable of testing the read-write performance of the router USB are edited; (104), the scripts are run, and a testing result is automatically output. The automatic testing system and method have the advantages that by the adoption of the BAT, portability is good, all platforms can be run, meanwhile, efficiency is high, a lot of manual testing work can be replaced, repeated testing is avoided, and a lot of labor is saved; precision is high, expandability is good, the cost is lowered, the testing efficiency is improved, existing resources can be better utilized, and time needed for putting the product into the market is shortened.