A two-pipe enhanced-vapor-injection outdoor unit and a two-pipe enhanced-vapor-injection multi-split system are provided. The two-pipe enhanced-vapor-injection outdoor unit includes an outdoor heat exchanger, an enhanced-vapor-injection compressor, a reversing assembly, a super cooler, a throttling assembly and a first pipe. The reversing assembly includes a first end and a second end connected with a gas discharge port and a gas return port, respectively. A main heat-exchange flow path is connected with the first port and the second port, respectively. An auxiliary heat-exchange flow path is connected with the injection port. The throttling assembly includes two ends connected with an outlet of the main heat-exchange flow path and an inlet of the outdoor heat exchanger. The first pipe includes a first end connected with an outlet of the outdoor heat exchanger, and a second end arranged between the throttling assembly and the main heat-exchange flow path.