The invention discloses a micro inflation device. The micro inflation device comprises a valve body and an airbag. The valve body is provided with a hollow cavity body. An air inlet which communicates with the hollow cavity body is formed in the upper end of the valve body. An air outlet which communicates with the hollow cavity body is formed in the left end of the valve body. An airbag connection port which communicates with the hollow cavity body is formed in the right end of the valve body. An air inlet valve unit is arranged in the air inlet. An air outlet valve unit is arranged in the air outlet. The airbag connection port is connected with the airbag. A rotatable end cover is arranged on the outer side of the air inlet valve unit. The size of the device can be reduced by 40%. According to the device, the end cover capable of preventing air leakage is connected in a threaded mode, and when the device needs to be sealed, a user can screw the end cover tightly; and when the device needs to be deflated, the user can reversely rotate the end cover, so that the poor sealing condition which is liable to occur in the prior art is avoided through the arrangement. An elastic face is arranged on the circular top wall of the end cover, deflation can be achieved by directly pressing the circular top wall, and operation is easy; and preferably, a buckle structure is arranged so that the end cover cannot be separated from the side wall of an air inlet valve, and the possibility of loss of the end cover is eliminated.