A method for tight interworking processing, performed by a first base station, characterized by comprising: transmitting, to a second base station, association information between first cells and second cells to inform the second base station on specific neighbour relation between the second cells requested by the first base station, that belong to the second base station, and the first cells belonging to the first base station, for tight interworking; wherein the association information between the first cells and the second cells comprises: a correspondence between each first cell of the first cells and the second cell requested by the each first cell; or, the association information between the first cells and the second cells comprises: a correspondence between each second cell of the second cells and all first cells requesting the each second cell; wherein the association information between the first cells and the second cells comprises an identity of each first cell and an identity of each second cell; wherein the method further comprises: transmitting, based on a measurement report received from a user equipment, a secondary gNB, SgNB, addition request message to the second base station, wherein the SgNB addition request message carries an identity of a serving cell of the user equipment under the first base station and a physical layer cell identity, PCI, of a target secondary cell group, SCG, cell, wherein the serving cell is a cell from the first cells; receiving an SgNB addition response message returned by the second base station, wherein the SgNB addition response message carries an identity of a third cell found by the second base station based on the identity of the serving cell, the PCI of the target SCG cell and the association information between the first cells and the second cells, wherein the third cell corresponds to the serving cell; and performing tight interworking configuration for the user equipment based on the identity of the third cell; wherein the identity of the each first cell is a unique identity of the cell and comprises: an evolved universal mobile telecommunications system terrestrial radio access network cell global identifier, ECGI; or, a PCI and a frequency; the identity of the each second cell is a unique identity of the cell and comprises: a new radio cell global identifier, NR-CGI. wherein the association information between the first cells and the second cells comprises: a correspondence between each first cell of the first cells and the second cell requested by the each first cell; or, the association information between the first cells and the second cells comprises: a correspondence between each second cell of the second cells and all first cells requesting the each second cell; wherein the association information between the first cells and the second cells comprises an identity of each first cell and an identity of each second cell; wherein the method further comprises: transmitting, based on a measurement report received from a user equipment, a secondary gNB, SgNB, addition request message to the second base station, wherein the SgNB addition request message carries an identity of a serving cell of the user equipment under the first base station and a physical layer cell identity, PCI, of a target secondary cell group, SCG, cell, wherein the serving cell is a cell from the first cells; receiving an SgNB addition response message returned by the second base station, wherein the SgNB addition response message carries an identity of a third cell found by the second base station based on the identity of the serving cell, the PCI of the target SCG cell and the association information between the first cells and the second cells, wherein the third cell corresponds to the serving cell; and performing tight interworking configuration for the user equipment based on the identity of the third cell; wherein the identity of the each first cell is a unique identity of the cell and comprises: an evolved universal mobile telecommunications system terrestrial radio access network cell global identifier, ECGI; or, a PCI and a frequency; the identity of the each second cell is a unique identity of the cell and comprises: a new radio cell global identifier, NR-CGI. transmitting, based on a measurement report received from a user equipment, a secondary gNB, SgNB, addition request message to the second base station, wherein the SgNB addition request message carries an identity of a serving cell of the user equipment under the first base station and a physical layer cell identity, PCI, of a target secondary cell group, SCG, cell, wherein the serving cell is a cell from the first cells; receiving an SgNB addition response message returned by the second base station, wherein the SgNB addition response message carries an identity of a third cell found by the second base station based on the identity of the serving cell, the PCI of the target SCG cell and the association information between the first cells and the second cells, wherein the third cell corresponds to the serving cell; and performing tight interworking configuration for the user equipment based on the identity of the third cell; wherein the identity of the each first cell is a unique identity of the cell and comprises: an evolved universal mobile telecommunications system terrestrial radio access network cell global identifier, ECGI; or, a PCI and a frequency; the identity of the each second cell is a unique identity of the cell and comprises: a new radio cell global identifier, NR-CGI.