The invention relates to a reverse-flow type frequency conversion speed regulation multi-fan array wind tunnel and a test method thereof. The wind tunnel is a hollow-square structure integrally and comprises a multi-fan power section (1), a first test section (2), a first corner (3), a first reverse-flow section (4), a second corner (5), a stable section (6), a contraction section (7), a second test section (8), a first expansion section (9), a third corner (10), a second expansion section (11), a fourth corner (12) and a second reverse-flow section (13) which are sequentially connected. The adaptive control technology is employed to realize frequency conversion speed regulation of a multi-fan system, the first test section and the second test section are adjusted according to test objects; the reverse-flow type and double-test section modes are employed, and properties of small energy loss and wide application field are realized.