Annealing furnace is a continuous hot-dip galvanizing cold-rolled production line in the important equipment, furnace atmosphere directly affect the product surface vacuum annealing furnace quality. At present, the production of high-end automotive plate furnace atmosphere demanding, the general requirements of residual oxygen below 10ppm, the dew point below -40 ℃. Furnace atmosphere depends largely on the good or bad air tightness of the furnace itself. Continuous annealing furnace air tightness check the main difficulty is that the furnace area is large, complex pipes, there may be many parts of the leak. The inspection of gas-tight rotary arm-type pit annealing furnace should be regularized and institutionalized.