A refrigeration system and a heat exchanger are provided. The refrigeration system includes a compressor, a micro-channel condenser, a micro-channel evaporator and at least one throttling device which are connected by pipelines. Each of the micro-channel condenser and the micro-channel evaporator includes an inlet manifold and an outlet manifold, and a plurality of flat tubes being connected between the inlet manifold and the outlet manifold. The inlet manifold of the micro-channel evaporator is provided with a baffle, and the inlet manifold of the micro-channel evaporator is divided by the baffle into multiple manifold sections, and the manifold sections of the inlet manifold are isolated from each other by the baffle, and are each in communication with a certain number of the flat tubes, and are each not provided with a distribution pipe configured to distribute flow rate into the flat tubes in communication with the manifold sections.