Disclosed are a key updating method and device, and a master Transmission Point (TP). The method includes: receiving a key parameter for generating a data encryption key of a TP in a virtual cell (S102); and generating the data encryption key of the TP in the virtual cell according to the key parameter and a cell Identity (ID) of the virtual cell (S104). By means of the key updating method and device and the master TP, the problem about key updating of different TPs in a virtual cell is solved.