In view of the situation that two employees need to manually operate the cantilever crane and the tightening machine to complete the alignment between the tightening shaft sleeve and the bolts to be tightened,and the nut reaction force mechanism is clamped and unloaded manually,which leads to the large manpower input and low production efficiency,a kind of automatic tightening machine for the bolts of the lower center plate based on machine vision was designed.Through the automatic identification of bolt position and bogie model,automatic contraposition tightening,automatic clamping and unloading reaction force mechanism,the humanless operation of the bolts tightening process of the lower center plate was realized,and the operation efficiency of the lower center plate bolts tightening was greatly improved.