A wireless transmission system includes several candidate devices, a wireless transmission interface and a wireless transmission device. The wireless transmission device includes a storage unit, a transmission direction information generating unit and a processing unit. The processing unit receives the device information of each of the candidate devices from each of the candidate devices respectively through the wireless transmission interface. The processing unit calculates transmission direction range according to the transmission direction information, which is generated through the transmission direction information generating unit. The processing unit selects at least one of the candidate devices, which matches the transmission direction range. Wherein, the selected at least one candidate device is taken as at least one transmission target device. The processing unit transmits the information to be transmitted, which is stored in the storage unit, to the transmission target device through the wireless transmission interface.