Kan Hua Zen is the typical model of Zen Buddhism after the Song Dynasty. Its system had been perfected by Da Hui who lived in Song Dynasty. The system may be summarized as follows: Ideological preparation before enter Zen meditation. The preparation includes two aspects: one is encouraging the faith; the other is knowing the theories of Buddhism well. Encouraging the faith is to encourage the pupils to practice the doctrine. Knowing the theories of Buddhism well is mainly to obtain the thinking method of Zen Buddhism. In Da Hui`s option, both are the needs to enter Zen meditation. Particularly it is the foundation of the mental operation that holds Buddhism theories when one is entering the meditation of Zen. The relationship between meditation of Kan Hua(meditate Hua Tou) and Buddhism theories. Kan Hua is a method to practice Mahayana. What Hua Tou represents is the core of the Mahayana theories-the thought of noumenon. The Hua Tou(a sentence said by a Zen teacher) used by Zong Gao included "Cypress seeds in court", "To drink off the west river`s water in one mouthful", "A dog does not own Buddhata" etc. What every one of these Hua Tou expresses is noumenon. According to Mahayana theories, all the worlds are mental states. And so the key of practice moral teachings is to carry out the reversal of the consciousness. To meditate Hua Tau is a method to carry out the reversal of the consciousness. It is a perfect procedure to combine the process of the preparation of mind to Kan Hua in detail and evolution of psychology. The thought of awakening Self-cultivation. The thought of awakening self-cultivation is expressed in the sentence of "the self-will is free and unfettered". It is to protect the mental state of awakening that "the self-will is free and unfettered". Its basic direction is not arbitrary but clearing up sticking to something. Da Hui raised the awakening self-cultivation to the height matching the essence, making the mental activity connected with essence actively, To explain the awakening self-cultivation in the Mahayana`s inwardness theory, he made Ka Hua Zen theory perfect.