Aiming at the problem of large caisson volume,overweight weight and precast caisson pedestal in an ore wharf,the traditional method of using air bag to jack up at one time can not be adopted.By adopting a new method of jacking up at the same time,the problem of insufficient air bag jacking and inability to jack up large and overweight caisson is solved.The results show that by adjusting the aeration pressure of the air bag at the bottom of the caisson,alternate jacking up of the caisson before and after can be achieved.By this method,the air bag need not to be in the state of super-high pressure,and it can meet the filling pressure requirements of the air bag relatively quickly.It can be used as reference for the large-scale caisson construction.