The foundation for a woman’s reproductive function is laid in the fetus, and all of her oocytes are produced during her lifetime by adding value in the fetus. At birth, a newborn may have 100,000 to 500,000 undeveloped follicles (primary follicles), which are not added later. The primordial follicle has a central primary oocyte surrounded by a layer of spindle-shaped cells. At puberty, batches of primordial follicles begin to develop. In response to anterior pituitary gonadotropins, the spindle cells become square and change from a single layer to multiple layers. These cells contain many secretory granules, called granulosa cells. The granulosa cells continue to divide and gradually form a cavity in the cell cluster called the follicular cavity. The fluid within the cavity is called follicular fluid. In response to pituitary gonadotropins, the granulosa cells surrounding the follicle Friday work in concert with the follicular membrane cells to produce estrogen. At this point, the follicle develops into a growing follicle (secondary follicle), which can be 100-200 pM in diameter. The growing follicle continues to develop, increasing in size, increasing in follicular fluid, further expanding the follicular lumen, and pushing the oocyte to one side. The granulosa cells between the oocyte and the follicular cavity protrude into the follicular cavity to form an oocyte mound into which the increased number of oocytes is buried. The granulosa cells that surround the oocyte on Friday are arranged in a radial crown and form a zona pellucida between the radial crown and the oocyte. At this point, the follicle matures and moves to the surface of the ovary, where it is called a mature follicle. Under the action of pituitary gonadotropin and progesterone, the protein hydrolase activity in the follicular fluid is enhanced; the concentration of prostaglandins increases significantly; under the action of several factors, the follicular wall and the ovarian epithelium finally rupture, and the follicular fluid, oocytes together with the zona pellucida, the radial crown and a small portion of the oocytes leave the ovary and slowly enter the abdominal cavity, and this is how the ovary ovulates.