Abstract: A quickly-operated adaptor is provided. A blocking member is movable in the main body. When a joint of a gas-communicating member is received in an outlet chamber to drive the blocking member, a positioning sleeve positions the joint. The gas-communicating mechanism is movable between a third position and a fourth position. When the gas-communicating mechanism is located in the third position, the outlet chamber is communicated with a gas-releasing chamber via the gas-communicating mechanism. Whereby, spurting of the joint caused by residual of the gas can be prevented, and it is effective to unblock or block the gas flow in the gas-communicating mechanism simply via adjustment of a slidable sleeve.