The Greeks provided an ideal model of "classical beauty" for western art. They regarded the universe as a whole and a complete sacred order. The word "universe" itself contained the meaning of "harmony, quantity and order". Pythagoras, an early Greek philosopher, pointed out that number is the common law of music and the operation of celestial bodies in the universe, symbolizing the harmony between music and the universe, and man himself is a harmonious body. Once he meets the harmony of the outside world, he will feel and resonate, respond with one voice and seek the same goal. Democritus famously said, "Man is a small universe". In the eyes of the Greeks, good things are produced by the harmonious relationship between the parts of the whole, and the beauty of this harmony comes directly from the human body, which is a small universe and a small order in the big order of the universe. They believe that the human body is beautiful, it is the best unity of truth, goodness and beauty, it embodies the wisdom and order that can be found in the universe and is the source of all goodness and beauty. Therefore, artists extend this concept to architecture, sculpture art and other aspects, and use human sculpture to express the image of God in their minds, thus symbolizing the sacred order of the universe. Ancient Greek sculptors repeatedly explored the standard proportion of human body in order to seek a human body standard that expresses beauty. The sculptor Poliklitos specially studied the proportions of all parts of the human body and wrote the book Rules, which clearly pointed out the proportional symmetry data of all aspects of the human body. For example, the height of a strong human body is seven heads long (7: 1), and the center of gravity of the statue is concentrated on one foot and the other foot is relaxed, which can highlight the tension and relaxation of the muscles and tendons of the whole body and make the whole image more expressive. In Poliklitos' masterpiece The Lancer, he created a noble and solemn ideal human image with a head-to-body ratio of 1:8.