1、意思不同。
too much和too many 在意思上都可以解释成：太多。much too解释成：太。
2、修饰的词不同。
too much修饰不可数名词，放在名词前面。如：too much water太多水。
too many修饰复数可数名词，放在名词前面。如：too many apples太多苹果。
much too修饰形容词，放在形容词的前面。如：much too fat 太胖。
3、用法不同。
much too＝too，但前者语气更强；too much＝much，但前者语气更强。
例句：
1、There ar too many books in the bookshop.书店有太多书。
2、There is too much water on the ground.地上有太多水。
3、I have too much salt.我有太多的盐了。（盐是不可数名词）
4、I have too many cups.我有太多的杯子了。（杯子可数名词）
5、He's much too young.他太年轻了。
6、The shoes are much too small for me.这鞋子我穿太小了。
没有many too这个结构。
too much，too many和much too的区别是：用法不同、词性不同。
一、用法不同
1、too many+可数名词复数，表达“太多”。例：
I have eaten too many sandwiches.我已经吃了太多的三明治。
2、too much+不可数名词，表达“太多”；在句尾作副词，表达“太、非常”。例：
Don't drink too much cola.不要喝太多的可乐。
3、much too+形容词／副词，表达“太”。例：
She is much too fat now.她现在太胖了。
二、词性不同
too much常用作副词或代词，也可以用作形容词。
much too常作副词。
too many常用作形容词。
词义辨析
much，a great deal of，a lot of，a number of，lots of，many，many a这组词（组）都表示“许多”的意思。其区别在于：
many是普通用语，其后只能接可数名词复数。
many a是书面用语，后接单数可数名词，当修饰主语时谓语动词要用单数形式。
much是普通用语，是对量和程度而言的，只能修饰不可数名词。
a number of可用来修可数名词复数。
a lot of和lots of既可接可数名词，也可接不可数名词，多用于肯定句。
a great deal of后接不可数名词，谓语动词用单数，且常用于肯定句中。
2、修饰的词不同。
too much修饰不可数名词，放在名词前面。如：too much water太多水。
too many修饰复数可数名词，放在名词前面。如：too many apples太多苹果。
much too修饰形容词，放在形容词的前面。如：much too fat 太胖。
3、用法不同。
much too＝too，但前者语气更强；too much＝much，但前者语气更强。
例句：
1、There ar too many books in the bookshop.书店有太多书。
2、There is too much water on the ground.地上有太多水。
3、I have too much salt.我有太多的盐了。（盐是不可数名词）
4、I have too many cups.我有太多的杯子了。（杯子可数名词）
5、He's much too young.他太年轻了。
6、The shoes are much too small for me.这鞋子我穿太小了。
too much+不可数名词
much too + 形容词/副词的原级
too much. too many, much too的用法和区别
too much + 不可数名词
They bumped her off because she knew too much.
因为她知道太多，所以他们把她干掉了。
Seeing too much violence on television can desensitize people to it.
在电视上看太多暴力，会使人对暴力麻木不仁。
They bumped him off because he knew too much about their illegal activities.
他们把他谋杀了， 因为他对他们的非法活动知道得太多了。
too many + 可数名词
They have too many restrictions.
他们有很太多的限制。
One reason for my decision was that all too many people advised me not to do it.
我之所以做出这样的决定，原因之一就是有太多的人不想让我来这里。
Versatility is another of your strong points, but don't overdo it by having too many irons in the fire.
你还有一个长处是多才多艺， 但不要揽事太多而太露锋芒。
much too + 形容词 很，非常….
One of the big mistakes that I think people make is to do too much too soon.
我认为人们常犯的一个大的错误就是在太短的时间里做得太多了。
Look, " he said to his people, "the Israelites have become much too numerous for us.
对他的百姓说：“看哪，这以色列民比我们还多，又比我们强盛。
For example, all of these elements are unlikely to be implemented as a
single component, since they're much too complicated for this to be the
case.
例如，所有这些元素都不可能作为一个单一的组件被实现，但是这对于一个用例来说太过复杂了。本回答被提问者和网友采纳
much too ：意义重点在 too 上，too---太，much 是个副词，修饰“太”的程度，整个短语有“过分”之意。
所以，区分这两个词组，只需要记住一点：语义重点，都在后面那个词身上