Zhou Pi Ai ·suan Jing is the earliest arithmetic classic in China history. Zhou is round and his moustache is wispy. It records the dialogue between Duke Zhou and Shang Gao, including the earliest written record of Pythagorean theorem, namely "three strands, four strings and five", also known as Shang Gao theorem. In fact, this must move forward in time. The book "Parallel Calculation of Weeks" adopts the simplest and feasible method to determine the astronomical calendar, and reveals the operating rules of the sun, the moon and the stars, including the changes of seasons and climate, as well as the fact that the north and south poles push each other day and night. It provides a powerful guarantee for the life and rest of the latecomers. Since then, mathematicians of all ages have been innovating and developing on the basis of the Classic of Weekly Parallel Computing. The classic of parallel computing in Zhou Dynasty embodies the hard work and wisdom of the people of China, which is an immortal monument of ancient science and technology in the world.