到底是the secret to doing还是the secret to do?

是the secret to doing，the secret to do 是错的。

这里to是介词，the secret to后面接名词，后面要用名词或者动名词。

意思是做...的秘密。

例句

1、He looks like a man who's found the secret to eternal youth. 

他看上去像是一个找到了永葆青春秘诀人。

2、The secret to avoiding this kind of problem is careful pre-planning of your meeting.

避免这类问题的秘密是细心地做好计划。

3、The secret to becoming a loving, nurturing being is just as simple as that. 

秘密就是成为一种爱，培养人，就是那么简单。

4、The secret to preventing and predicting obesity has been revealed by a team ofMelbourne researchers, who believe stress and how we respond to it is the key factor to managing our weight. 

一只来自墨尔本的研究团队找到了预测和预防肥胖的秘密。他们相信，控制体重的关键因素是我们感受到的压力和我们对压力的应对之道。

5、This is the secret to achieving consistent success as a trader. 

这是成为持续一致的成功交易者的秘诀。

the secret to doing。

这里to是介词，后面要用名词或者动名词。意思是做...的秘密

1. He looks like a man who's found the secret to eternal youth.
   他看上去像是一个找到了永葆青春秘诀人。

2. The secret to avoiding this kind of problem is careful pre-planning of your meeting.
   避免这类问题的秘密是细心地做好计划。

3. The secret to becoming a loving, nurturing being is just as simple as that.
   秘密就是成为一种爱，培养人，就是那么简单。

4. The secret to preventing and predicting obesity has been revealed by a team ofMelbourne researchers, who believe stress and how we respond to it is the key factor to managing our weight.
   一只来自墨尔本的研究团队找到了预测和预防肥胖的秘密。他们相信，控制体重的关键因素是我们感受到的压力和我们对压力的应对之道。

5. This is the secret to achieving consistent success as a trader.
   这是成为持续一致的成功交易者的秘诀。

是the secret to doing。

这里to是介词，后面要用名词或者动名词。意思是做...的秘密。

例句：
1、He looks like a man who's found the secret to eternal youth.
他看上去像是一个找到了永葆青春秘诀人。
2、The secret to avoiding this kind of problem is careful pre-planning of your meeting.

避免这类问题的秘密是细心地做好计划。
3、The secret to becoming a loving, nurturing being is just as simple as that.
秘密就是成为一种爱，培养人，就是那么简单。
4、The secret to preventing and predicting obesity has been revealed by a team ofMelbourne researchers, who believe stress and how we respond to it is the key factor to managing our weight.

一只来自墨尔本的研究团队找到了预测和预防肥胖的秘密。他们相信，控制体重的关键因素是我们感受到的压力和我们对压力的应对之道。
5、This is the secret to achieving consistent success as a trader.

这是成为持续一致的成功交易者的秘诀。