Compressor module, multi-module unit and oil-balancing control method for multi-module unit

A compressor module comprises at least two compressors (1, 2) both provided with an oil-balancing hole and connected in parallel to each other; an oil separator (4) with an inlet communicated with the discharge ports of the at least two compressors (1, 2) and an oil-return port communicated with the suction ports of the at least two compressors (1, 2); and a first oil-balancing pipe with the first end communicated with the oil-balancing holes of the at least two compressors (1, 2) and the second end communicated with the inlet of the oil separator (4).