A multiple output universal serial bus travel adaptor includes: at least one AC-DC converter for converting an AC power to a first DC power; at least one DC-DC converter for providing a second DC power according to the first DC power; plural switches which are coupled to the AC-DC converter and/or the DC-DC converter to provide the first DC power or the second DC power to corresponding connectors according to operation signals; and a protocol controller configured to generate the operation signals according to at least one of the following parameters: a) the types of the connectors; b) whether there is a mobile device connected with the connectors; c) a first command from the mobile device; d) the power consumed by the mobile devices; e) the currents flowing through the connectors; and f) the voltages at the connectors.