Yuan Shikai did this because he was superstitious. When he was strong, he had already given birth to the idea of usurping the Qing dynasty, and then according to Feng Shui master, his ancestral grave was about to be stripped.
In fact, Yuan Shikai was superstitious since he was a child. When he is doing things, he often looks at fortune tellers and measures geomantic omen. At that time, Yuan Shikai was forced to go home to recuperate. Yuan Shikai stubbornly believed that there must be something wrong with his ancestral grave, so he invited a famous Feng Shui gentleman to measure the Feng Shui of his ancestral grave to solve the problem. Mr. Feng Shui looked at it and said, "Yuan Jiazu's grave is a real dragon knot, which is extremely expensive. However, due to the wall around the dragon cave, the dragon body was bound and blocked, unable to flourish and frustrated. It is imperative to tear down the wall of the ancestral grave. " Yuan Shikai believed it directly. After all, he himself had been exposed to this knowledge for a long time, so he felt that the Feng Shui master was right, so he sent someone to tear down the wall of his ancestral grave to make it look more upright, more like a dragon, and make Long Mai more prosperous. So there appeared a folk fable: Yuan Shikai dug graves for his ancestors.
In fact, Yuan Shikai is superstitious about this geomantic numerology. When Yuan Shikai was the president of the Republic of China, Wu Dingchang, a talented person, was recommended as the chief financial officer. So Yuan Shikai summoned Wu Dingchang, but his face was not good. Yuan Shikai thought that he could see his cheeks behind him, and Cao Cao was such a face. Talents were not reused, and Wu Dingchang later became only the director of a mint. From this incident, we can intuitively see how powerful Yuan Shikai's superstition is.