The invention discloses a method for cutting out garments according to a figure based on millimeter waves. The method comprises the specific steps that 1, a measured person stands according to a certain standing posture rule, three-dimensional data of the human body is obtained, the data matrix size is (Nz, Nx, Ny), and the data is normalized; 2, the data, in the X direction and the Y direction, of the human body is obtained through a positive projection, such as the body height, the arm length, the shoulder width and the head circumference; 3, the circumference data of the human body is obtained through a lateral projection, such as the hip circumference, the waist circumference, the waist height, the chest circumference and the abdomen circumference. In the method, the good characteristics of the millimeter waves are fully utilized, by using a micro-wave imaging technology, it is achieved that the contactless three-dimensional data of the human body is obtained, the related dimensions of the human body are quickly analyzed, and it is achieved that the garments are cut out according to the figure; the overall speed of obtaining and calculating original image data is high, and thewhole figure measuring process is completed within 5 seconds.