Abstract: A method and an apparatus for data transmission between a contactless front element and a security element are provided. The method includes: the contactless front element transparently transmits first data obtained from a contactless identification device to the security element through a single wire connection; the security element processes the first data to generate second data; the contactless front element transparently transmits the second data obtained from the security element through the single wire connection to the contactless identification device. Compared with the prior art, the method can transmit the contactless data in real time between the contactless front element and the security element.