In Heroes (说英雄谁是英雄), Su Mengzhen dies before the story ends, so he does not get a happy resolution. The ending is tragic overall, with the main romantic pair surviving while Su Mengzhen is listed among the dead.

What happens to him

Su Mengzhen is involved in the central Jianghu conflicts, and later recap material shows him still fighting, taking losses, and getting pulled deeper into the chaos around Lei Chun, Bai Choufei, and Wang Xiaoshi. One recap also notes that after major betrayals and battles, Su Mengzhen is among the characters who die by the end.

Why people remember his ending

A lot of viewers fixate on Su Mengzhen because his story feels especially painful: he is loyal, burdened by duty, and repeatedly forced into impossible choices. The ending is widely described as sad and incomplete in the emotional sense, even if the plot itself reaches a clear finish.

Spoiler-friendly takeaway

If you only want the blunt answer: Su Mengzhen does not survive the drama’s ending. If you want, I can also give you a fuller spoiler summary of his final arc with Bai Choufei and Lei Chun.