A pneumatic valve adaptor includes a fast-releasable gas source connector, which includes a top source piece and a rotatable joint, the and at least one valve coupler. The top source piece is connected to a top end of the rotatable joint for receiving and feeding gas supplied from a gas source into the rotatable joint. The rotatable joint has a lower edge in which at least one first engagement section is formed. The valve coupler is provided, at a lateral external surface and a lower end, with at least a second engagement section and a valve connection section. The second engagement section is engageable with or disengage able from the first engagement section through rotation of the rotatable joint. The valve connection section is connectable to a pneumatic valve of an inflatable object for supplying and feeding the gas from the gas source into the inflatable object for inflation.