The utility model discloses a self-adaptive transmission device with a full-center positioning function and capable of solving unbalance loading of double intermediate shafts. The self-adaptive transmission device comprises an input shaft, the input shaft is sleeved with the first input gear, the first input gear is driven by the input shaft, and the first input gear is provided with a mounting boss; the second input gear sleeves the mounting boss; the first intermediate shaft and the second intermediate shaft are arranged on the two sides of the input shaft respectively. The first intermediate shaft transmission gear is arranged on the first intermediate shaft, and the second intermediate shaft transmission gear is arranged on the second intermediate shaft; the first intermediate shaft gear gear is arranged on the first intermediate shaft and synchronously rotates with the first intermediate shaft, and the second intermediate shaft gear is arranged on the second intermediate shaft andsynchronously rotates with the second intermediate shaft; the output gear gear is simultaneously meshed with the first intermediate shaft gear gear and the second intermediate shaft gear gear; and the output shaft and the output gear gear rotate synchronously. The self-adaptive transmission device can solve the problem of unbalance loading of double intermediate shafts, and is convenient to machine and produce and good in stability.