Wang Jin is the first hero introduced at the beginning of Water Margin, so people who have seen Water Margin should have an impression on him. The opening story is about Wang Jin passing by downtown. When he saw the rogue Gao Qiu running amok, he stepped forward to stop him and gave him a beating. Later, Qiu Shuai, an official in Gao Qiu, wanted to harm Wang Jin, but Wang Jin fled with his old mother. On the way to escape, Wang Jin passed by Shijiazhuang, taught him martial arts, and then went to Yan 'an to talk with the old man. Since then, he has never been mentioned in the book.

As for Wang Jin, he is neither one of the heroes of 108 in Water Margin nor the enemy of Liangshan heroes. On the contrary, he is inextricably linked with Liangshan heroes. He is the master of Liangshan heavyweight Shi Jin, and his second appearance in Water Margin leads to a rare real hero Lu in Liangshan. But this character was anticlimactic in Water Margin, and began to be introduced in detail, including his feud with Gao Qiu and his escape. And his whereabouts are exactly the same as those of Liangshan heroes introduced later. He took his mother to Yan 'an Mansion to take refuge in the old-fashioned running group, and stayed at home for the night, which led to the story of Shi Jin worshipping Wang Jin as an apprentice. Shi Jin's kung fu was among Liangshan heroes. Later, Zhu Wu, Chen Da and Yang Chun, the three outstanding figures in Shaohua Mountain, became attached to them because of Shi Jin. Then Shi Jin couldn't find a teacher, met Lu, and then deduced a series of stories of Lu until he met Lin Chong, thus starting the story of Liangshan heroes gathering. Therefore, in the Water Margin, Wang Jin is a heavyweight. However, at the end of the story, Wang Jin never appeared again. Even if Shi Jin tried every means to find him, there was no trace of him. From then on, there was no news of Wang Jin.

As Shi Jin's master, Wang Jin taught Shi Jin eighteen martial arts in only half a year, and his martial arts level can be seen. It can be said that Wang Jin won't lose if he fights with other heroes in the Jianghu. As a result, Wang Jin's martial arts level must be no less than Shi Jin. So, how strong is Wang Jin's martial arts level?

Among Liangshan heroes, only Lu Junyi is not inferior to coach Lin in martial arts. Lu Junyi, nicknamed "Yu Qilin", has high martial arts and is a big talker. Known by Jianghu people as "Hebei Three Musts", he later became the second leader of Liangshan. Compared with Wang Jin's martial arts level, Lin Chong and Guan Sheng were both defeated by Wang Jin, so Lu Junyi's level should be almost the same as Wang Jin's at most, and it can be tied at most.