The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing MCG recovery in dual connectivity in wireless communication system, the method comprising: detecting radio link failure on a master node, wherein the UE is configured with the master node and a secondary node simultaneously; and suspending all secondary cells of the secondary node during the RRC connection re-establishment procedure, and transmitting an indicator indicating the suspension of secondary cells of the secondary node without releasing the secondary cells if the selected cell is one of cells belonging to a cell list.