The invention discloses a pre-evacuating treatment apparatus for a flexible strip by vacuum sputtering, comprising a vacuum pump and a plurality of groups of pre-vacuumizing tanks. The plurality of pre-vacuumizing tanks are connected with the vacuum pump and can separately turn on and turn off to vacuumize; the pre-vacuumizing tanks are connected with an air exhaust pipe through a separate evacuation valve and provided with air intake pipes through an inflation valve; a mandrel for installing a flexible strip coil is arranged in each pre-vacuumizing tank, and each pre-vacuumizing tank is alsoprovided with a vacuum gauge; and the vacuum pump is provided with a main evacuation valve. The invention has the advantages of successfully evacuating the air and volatile gas inside the flexible strip, thereby improving evacuation speed of the vacuum sputtering, reducing the energy consumption of the apparatus, improving adhesion of target particles, improving infiltration of the finished product, and improving the product quality of the vacuum sputtering.