do sb good 对某人有用；对某人有好处(这里的 good 是不可数名词)：

A bit more exercise would do you good. 稍微多锻炼锻炼对你有好处。（摘自《朗文当代高级英语辞典》第六版）

Much good has it done him. = Much good  it has done him.= It has done him much good.

这事已经给他带来了很多好处。

【说明】Much good has it done him. 和 Much good  it has done him.这两个句子的结构叫做“宾语前置”（Much good 是宾语），在这种情况下，句子的主语和谓语通常不倒装，有时也可以倒装。