Who killed Zhu Siping in The Five Years Stolen?

It was Long Xiaoyu who killed him. Daxiong stabbed him first, and Long Xiaoyu made up the fatal knife.

Actually, that night, Zhu Siping was seriously injured at first (stabbed by Daxiong and others with a knife). Later, Long Xiaoyu came to the crime scene. Zhu Siping was still alive and asked Long Xiaoyu for help.

in order to get rid of Zhu Siping's entanglement completely, Long Xiaoyu gave Zhu Siping a knife in a moment. Is Long Xiaoyu this key knife, let wish four ping to death. So Zhu Siping was killed by Long Xiaoyu.

their emotional history:

Zhu Siping and Long Xiaoyu are fellow villagers in the same village. They grew up together in the troupe.

After Long Xiaoyu's mother eloped with others, his father died of illness when he was in high school. It was Siping who paid for Long Xiaoyu's education by working in a factory. Until Long Xiaoyu's sophomore year, Siping's mother fell ill and Long Xiaoyu dropped out of school to help take care of Siping's mother.

Later, the two men came to Xiamen to work, and under the leadership of Zhang Xiong, the foreman of the same village, they met Luo Jingjing in a way of "touching porcelain".

Originally, I wished Siping and Long Xiaoyu a plan to get close to Luo Jingjing, and then Long Xiaoyu got economic benefits by fake marriage, but Siping didn't expect Long Xiaoyu to really fall in love with Luo Jingjing, which finally led to tragedy.