Wonhyo spent the earlier part of his career as a monk studying under various Korean Buddhist teachers and living in Hwangnyongsa Temple.

[1] One of the most famous episodes of Wonhyo's life, found in various hagiographical accounts, is the story of his aborted attempt to travel to Tang China to study the Yogācāra teachings of the school of Xuanzang (602–664).

[1] The story says that in 661 Wonhyo and a close friend called Uisang (625–702) were traveling to China, when, somewhere in the region of Baekje, the pair were caught in a heavy downpour and forced to take shelter in what they believed to be an earthen sanctuary.

[1][6] Startled by the experience of believing that a gruesome liquid was a refreshing treat, Wonhyo was astonished at the power of the human mind to transform reality.

As he reflected on this, he had a deep insight into how the world is a creation of mind and directly experienced the Yogacara principle of "mind-only" (cittamatra).

[1] While the orthodox Buddhist tradition discouraged such behaviors, his songs and dances were seen as upaya, or skillful means, meant to help save all sentient beings.

[7] At other times he lived alone in the mountains or along rivers, wrote various works and gave lectures on Buddhism and taught the people to chant the Buddha's name.

As noted by Hee-Sung Keel: Wŏnhyo, commonly regarded as the greatest thinker in Korean Buddhism, was a prolific writer who produced no less than eighty-six works, of which twenty-three are extant either completely or partially.

By his time, most of the important sūtras and treatises had flowed into Korea from China, and they were causing a great deal of confusion for Silla Buddhists, as they had for the Chinese.

[9]Wohnyo's collaboration with Uisang directly led to the establishment of the influential Hwaeom (Korean Huayan) school as a major stream of thought in Korea.

[1][2] Wonhyo was especially influenced by Buddha-nature literature, East Asian Yogācāra, Huayan thought and the philosophy of Essence-Function (Chinese: 體用).

Wonhyoʼs harmonization methodology is found in almost all his works and often expresses itself in a deep investigation of the root of seemingly conflicting Buddhist doctrines and positions.

So if you want [like Chih-i] to divide the scriptural meaning into four teachings, or limit the Buddha's intent with five periods, then this is like using a snail shell to scoop out the ocean, or trying to see the heavens through a narrow tube.

Wonhyo often traces the origin of intra-Buddhist doctrinal conflict to a misunderstanding of linguistic conventions like difference and sameness, and affirmation and negation.

[13] Another element of his harmonization method was to draw on Huayan metaphysics of interpenetration to demonstrate how all Buddhist teachings are ultimately in a state of non-obstruction.

[15] The one mind (一心) theory is drawn from the influential treatise The Mahayana Awakening of Faith (大乘起信論; pinyin: Dàshéng Qǐxìn Lùn) and is discussed in Wonhyo's numerous commentaries.

For the commoners he generally taught a flexible teaching which included Buddhist metaphysics and the simple Pure Land practice of reciting the name of Amitabha with a sincere mind intent on bodhicitta.

[17] As noted by Charles Muller "except for the works of the extraordinarily prolific translators such as Kumārajīva (344–413) and Hsüan-tsang (596–664), this is probably the largest literary output by a single scholar in East Asian Buddhist history.

[3] His commentaries are often holistic ones, which, according to Robert Buswell, "seek to demonstrate, first, how each section, part, and division of the scripture resonates with the rest of the sections, parts, and divisions of the text; and second, how the text that is the focus of his commentary reticulates within the entire fabric of the Buddhist scriptural teachings...he attempts nothing less than to demonstrate that the entirety of Mahayana Buddhism is revealed in the single sūtra that is the focus of his exegesis.

The World Taekwondo Federation has a Hyeong or pattern named Ilyeo for 9th Dan black belt which means the thought of the Buddhist priest of Silla Dynasty, Wonhyo.

In 2011, retired Canadian journalist Tony MacGregor walked across the Korean Peninsula in an attempt to understand the awakening experience of Wonhyo.

MacGregor's journey, which involved staying at mountain monasteries and talking to monks, was the first in over 1,000 years to honor Wonhyo's accomplishment.