The full name of "Avataṃsaka Sūtra" is "the Mahāvaipulya Buddhāvataṃsaka Sūtra", which is one of the most important classics at the first stage of Mahayana Buddhism in India. It was the very time when the Buddha became enlightened for the first time in the bodhi field. As soon as the Buddha became enlightened, he proclaimed and preached what he had obtained from the enlightenment for such Bodhisattva as Mañjuśrī (曼殊師利菩薩) and Samantabhadra (普賢菩薩). Since the scriptures were passed on into China and were introduced to Han, they have been valued by the people from all walks of life. Therefore, Master Zong-mi in Tang Dynasty has ever said in "Abbreviated Commentary on the Vows of Bodhisattva Samantabhadra Sutra", volume two, "If you've not studied the Huayan Sutra yet, you'll never know how wealthy and splendid the Buddha is!" There are three Chinese versions of "Avataṃsaka Sūtra" in total, including (1) "the 60-fascicle Avataṃsaka", translated by Buddha Batuo during the Eastern Jin Dynasty, (2) "the 80-fascicle Avataṃsaka", translated by Shicha Nantuo during Queen Wu of the Tang Dynasty, and (3) "the 40-fascicle Avataṃsaka", translated by Master Prajna during the Tang Dezong period. Since the textual meanings in "the 80-fascicle Avataṃsaka" are more fluent and comprehensible, and the names of the volumes are more complete, so far it has been widely spread around. Therefore, this paper is mainly based on the Gandavyūha Chapter (入法界品) of "the 80-fascicle Avataṃsaka". The Gandavyūha (入法界品) is the last volume of the "Avataṃsaka Sūtra", which can be complimented as the condensed essential edition of the "Avataṃsaka Sūtra". The main content describes the course of Sudhana's fifty-three visits in the pursuit of what a Bodhisattva should practice and carry out. Initially, Sudhana's bodhicitta became enlightened through the guidance of Manjushri. After that, he managed to get close to the 53 great enlightened masters, and finally paid a visit to Samantabhadra. His experience on the same state of wisdom and virtue as the buddhas' is the so-called "Completing Gandavyūha", which begins with Mañjuśrī's great wisdom and is perfected with Samantabhadra's great wishes. The core figure of "Gandavyūha" is represented by Sudhana, who interprets the final chapter of the great "Avataṃsaka Sūtra". It follows that the above statement induces the author to further explore the 53 great enlightened masters in the "Gandavyūha". Therefore, the author's exploration include the 53 great enlightened masters' contents of the enlightenment and the quality of education, the particular teaching method, the deeper meanings, and Samantabhadra's practice. This paper also analyzes the practical significance of developing bodhicitta and following examples of great enlightened masters. And at the last part, the author has clarified the crucial thoughts in "Gandavyūha".