Disclosed is a method for conducting random access on a small cell under dual connectivity. The method includes that: a User Equipment (UE) sends a dedicated random access preamble corresponding to a designated small cell to a base station to which the designated small cell belongs on the designated small cell; and the UE receives a random access response message sent by a base station to which a master control cell in dual connectivity belongs or the base station to which the designated small cell belongs. The present disclosure also discloses a system for conducting random access on a small cell under dual connectivity, a base station, a UE and a computer storage medium.