The invention discloses a tunnel lining vault vibrating method. A vault vibrating device is mounted on a vault formwork at the top of a lining trolley. When vibrating operation is needed, an electricpush rod is started, and a vibrating rod mounting plate is pushed to move upwards along two guide rails and a vibrating rod is driven to move upwards and enter concrete under the action of pushing force of the electric push rod. When the vibrating rod mounting plate touches an upper limit switch, the electric push rod stops working, and the vibrating rod is powered on and started to perform the vibrating operation. The vibrating rod automatically stops working after preset vibrating time, and then the electric push rod is started to move reversely and drives the vibrating rod to move downwards. When the vibrating rod mounting plate touches a lower limit switch, the electric push rod stops working, the first vibrating operation of a position of a tunnel lining vault is finished, the first vibrating operation is repeated for several times under the condition of equal vibrating depth, and the vibrating operation on the whole tunnel lining vault can be finished.