Although these phrases are often used interchangeably they have slightly different meanings, so we should be careful how we use them.
在很多情况下，“According to”和“In accordance with”都可以互换，但是两者之间还是有一些细微的差别的。所以，在使用这两个词组时，我们需要特别小心。
How to use “According to”?
“According to…” is usually used when you restate something someone told you or something you have heard or read somewhere. It is mostly used for reporting.
EX：According to the clerk we spoke to when we telephoned the supervisory authority this morning, the application was filed last week.
It may be used to introduce information that might not be true:
EX：According to the state news agency, the number of demonstrators did not exceed 1,000. However, the organisers of the protest say there were at least 100,000 people on the march.
It may also be used to introduce hearsay:
EX：According to Annabel, Tom wants to dump Sarah because he really fancies Emma.
How to use “In accordance with”?
“In accordance with”的用法
“In accordance with…” is used in more formal contexts to introduce the notion of conformity. In a legal context it is used for stating what conforms to the law or a contract. It is never used to introduce information that may not be true.
“In accordance with”是用在比较正式的内容中，用来引述确实的信息。在法律文本中，这个词组就是用来引述法律条文或合同中的规定的。“In accordance with”从来不会用于引用不确实的消息。
EX：In accordance with Article 72 of the Act, employees of the Company have the right to form a representative body.
In some cases you can use “under…” instead of “in accordance with”, or where “in accordance with” seems too strong:
如果觉得用“in accordance with”语气太强烈的话，也可以用“under…”来替换。
EX：Under / In accordance with a general rule of the Pharmaceutical law, the sponsor and the investigator are responsible for damage resulting from conducting a clinical trial.
Using a comma with this type of clause
EX：According to recent government statistics, unemployment has risen from 3% to 5% over the last 12 months.