I am looking for an old TV series, a Hong Kong movie, a funny ghost movie about a Qing Dynasty man who helps students in a school after his death!

What the person above said is right, it is "Explanation of Sir's Ghost", also called "School Dragon"

That one is not the principal, but the dean of students, Ouyang Xiecheng

The first series tells the story of Pork Rong (played by Lu Haipeng), who was born in the late Qing Dynasty in China and was a kind-hearted man. One day, he was shot dead by a Western soldier to save his child. He left behind a pair of clogs after his death. As long as he used these The sound of clogs can recall the ghost of Pork Rong.

The story comes to Hong Kong in the 1990s, and there is a haunted middle school with a very long name: "St. Fran Yagen's Christian Mark Brode Saints' Asian Zhishan Church Dr. and Mrs. Sima Zhaozhao's First Memorial Middle School", The unscrupulous principal Liao Huizhu (played by Wu Wanyi) and the unscrupulous teacher dean Ouyang Xiecheng (played by Lu Haipeng) work together to bully the students. They often scold the students unreasonably and make them difficult, and use despicable methods to extort money from the students, such as Fines are used as punishment for "violating" "school rules".

One day, Ouyang Xiecheng was accidentally electrocuted to death. By some mistake, the ghost of Zhu Rong took Ouyang Xiecheng's body and acted as Ouyang Xiecheng as the dean of students. Pork Rong is kind-hearted and is kind and caring to his students. In the eyes of those who don't know, they think he is the unscrupulous teacher Ouyang Xiecheng who suddenly changes his personality. Zhu Ronggeng became friends with Cui Wenjian (played by Mo Jiayao) and several other naughty students, and spent a happy and noisy life.

In addition, when Cui Wenjian was still a child, he had a crush on his female classmate Wang Jialing (played by Wan Qiwen). Wang Jialing was an orphan. Cui Wenjian, who came from a wealthy family, used money to support Wang Jialing and used Uncle Man as the name. Under the pen name, I have been writing letters to Wang Jialing until now. Wang Jialing admires this donor and pen pal who calls himself Uncle Man very much, and hopes to meet him. However, this Uncle Man has been avoiding her. Wang Jialing also does not know that Uncle Man is Cui Wenjian. On the contrary, in daily interactions, he seems even more... He hates Cui Wenjian and bullies him a lot, which makes Cui Wenjian, who has a crush on Wang Jialing, miserable and causes many misunderstandings and jokes (it is generally believed that this plot is plagiarized from the American novel "Daddy Long Legs").

Unfortunately, good times do not last long. One day, Taoist priest Li Xueren (played by Luo Qinghao) passed by the school and discovered that Zhu Rong's ghost had taken up residence in Ouyang Xie Cheng. Li Xueren believed that Zhu Rong's move was against the laws of nature and cast a spell to drive it back to the underworld. Cui Wenjian and others were reluctant to part with their friend and wanted to recall him to the earth, but they mistakenly summoned Ouyang Xiecheng's ghost. After Ouyang Xiecheng was resurrected, he intensified his bullying and extortion of money from students. He even used despicable means to force students to work to make money for him. He even bought life insurance for all students in the school, and then caused accidents and killed students one by one in order to collect his money. Insurance compensation. It turns out that after Ouyang Xiecheng died, he committed evil in the underworld. After his resurrection, he unscrupulously used students to raise money for him. He planned to use the money in the underworld to recruit troops and then return to the underworld to rebel.

Soon, almost all the students in the school died in "accidents". Only Cui Wenjian and Wang Jialing were left. They cooperated with Li Xueren to recall the ghost of Zhu Rong. After everyone fought together, they finally recovered. Defeat Ouyang Xiecheng until he will never be reincarnated. The students who died due to "accidents" before were also "forced to be sent back" to the underworld by the underworld because they had not yet reached the end of their Yang lives.

Finally, Cui Wenjian, Wang Jialing and other students graduated and left school, Pork Rong also returned to the underworld to wait for reincarnation, and everyone reluctantly said goodbye.

The main shooting location is Clear Water Bay Sam Yuk Secondary School. This drama uses a lot of the soundtrack of the Moment of Togetherness animation