A hybrid vehicle mode shift control device comprises a drive force combining transmission that includes a differential gear device coupled to an engine, at least one motor, and an output member, an engine clutch configured to connect and disconnect the engine with the differential gear device, and a low brake configured to hold the drive force combining transmission at a lower side gear ratio. The hybrid vehicle is operated at least in an EV mode, an EV-LB mode, an E-iVT mode, and an LB mode. The hybrid vehicle mode shift control device comprises a mode shift control section configured to select one of a mode shift route passing through the E-iVT mode and a mode shift route passing through the EV-LB mode based on the transitional drive force request of the driver when a mode shift request is issued to shift from the EV mode to the LB mode.