A refrigerant distributor (4) includes: a box body (42); a refrigerant inlet (41) arranged on an upper surface (421) of the box body (42); liquid exit openings (46) evenly arranged on a lower surface (422) of the box body (42); and end plates arranged at both ends of the box body (42) in a length direction and enclosing the box body (42) from the two ends; wherein, in a height direction from the lower surface (422) of the box body (42) to the upper surface (421) and within a predetermined height range starting from the lower surface (422), a width of the box body (42) increases gradually; and a pre-distributor (3) is arranged inside the box body (42).