  The measurement-device-independent quantum key distribution (MDI-QKD) can be
immune to all detector side-channel attacks. Moreover, it can be easily
implemented combining with the matured decoy-state methods under current
technology. It thus seems a very promising candidate in practical
implementation of quantum communications. However, it suffers from severe
finite-data-size effect in most existing MDI-QKD protocols, resulting in
relatively low key rates. Recently, Jiang et al. [Phys. Rev. A 103, 012402
(2021)] proposed a double-scanning method to drastically increase the key rate
of MDI-QKD. Based on Jiang et al.'s theoretical work, here we for the first
time implement the double-scanning method into MDI-QKD and carry out
corresponding experimental demonstration. With a moderate number of pulses of
10^10, we can achieve 150 km secure transmission distance which is impossible
with all former methods. Therefore, our present work paves the way towards
practical implementation of MDI-QKD.
