A cooling system for a battery pack, comprising: a housing, an air passage, a fan and at least two air holes; the housing comprises an upper cover and a box, the upper cover is connected with the box; the air passage is arranged inside the box and comprises an airflow cavity, an air channel and the at least two air holes; the airflow cavity is arranged at a bottom of the box; the air channel is arranged on a side wall of the box, and a bottom of the air channel is in fluid communication with the airflow cavity; all the air holes are arranged on the housing and in fluid communication with the air passage, wherein at least one air hole is arranged on the upper cover and corresponds to a top end of the air channel; the fan is arranged inside the air passage; characterized in that: the cooling system for a battery pack further comprises: an air-cooling plate; the box comprises side walls and a bottom plate; the side walls enclose to form a barrel structure with two ends opened; the air-cooling plate is connected with bottoms of the side walls; the bottom plate is arranged inside the barrel structure and parallel to the air-cooling plate, and a gap is defined between the bottom plate and the air-cooling plate, such that the bottom plate, the side walls and the air-cooling plate together enclose to form the airflow cavity; a plurality of air flow limiting channels are arranged in parallel inside the airflow cavity, an end of the air flow limiting channel is in fluid communication with at least one of the air holes, and the other end of the air flow limiting channel is in fluid communication with at least one of the air holes; a separation plate extending perpendicularly to the air-cooling plate is arranged inside the airflow cavity, and the airflow cavity is separated by the separation plate into the plurality of air flow limiting channels; a sub-separation plate is arranged in the air flow limiting channel, the sub-separation plate extends along an extending direction of the air flow limiting channel and separates the air flow limiting channel into air flow limiting sub-channels in parallel. the cooling system for a battery pack further comprises: an air-cooling plate; the box comprises side walls and a bottom plate; the side walls enclose to form a barrel structure with two ends opened; the air-cooling plate is connected with bottoms of the side walls; the bottom plate is arranged inside the barrel structure and parallel to the air-cooling plate, and a gap is defined between the bottom plate and the air-cooling plate, such that the bottom plate, the side walls and the air-cooling plate together enclose to form the airflow cavity; a plurality of air flow limiting channels are arranged in parallel inside the airflow cavity, an end of the air flow limiting channel is in fluid communication with at least one of the air holes, and the other end of the air flow limiting channel is in fluid communication with at least one of the air holes; a separation plate extending perpendicularly to the air-cooling plate is arranged inside the airflow cavity, and the airflow cavity is separated by the separation plate into the plurality of air flow limiting channels; a sub-separation plate is arranged in the air flow limiting channel, the sub-separation plate extends along an extending direction of the air flow limiting channel and separates the air flow limiting channel into air flow limiting sub-channels in parallel.