A method for constructing a map for a mower includes: acquiring a preliminary map of a work region, two adjacent target points are used as first target points and are connected to form an initial connecting line; selecting a target point farthest from the initial connecting line as a second target point, and using a connecting line between the second target point and the first target points as to-be-processed connecting lines; selecting a third target point for each to-be-processed connecting line; when a condition is met, using connecting lines between the third target point and the target points at the two ends of the to-be-processed connecting line as new to-be-processed connecting lines and returning; retaining each of the third target points whose distance from a corresponding to-be-processed connecting line is greater than the first preset threshold as a map construction target point, and constructing a boundary map.