Heat exchanger module, heat exchanger and air conditioning system

The utility model discloses a heat exchanger module, a heat exchanger with the heat exchanger module and an air conditioning system with the heat exchanger module or the heat exchanger. The heat exchanger module includes: a heat exchange tube; a main header connected to and in fluid communication with the ends of the heat exchange tubes; and the auxiliary collecting pipe is connected with the main collecting pipe and is in fluid communication with the main collecting pipe, and the length of the auxiliary collecting pipe is smaller than that of the main collecting pipe. The heat exchanger may be formed by connecting a plurality of heat exchanger modules using the sub-header.