Hi Zhanzhang,
I looked in more detail at the area of interest. I downloaded the B08 from EO Browser and also from Scihub too. There are actually two tiles that can be downloaded over this area of interest. One is in UTM zone 33N and the other UTM zone 34N. In addition, I downloaded the data using Sentinel Hub’s Process API in those projections to compare the values. All the data downloaded was L2A. The results of which are below:
So yes, there is a difference between the Scihub and the data from Sentinel Hub in this instance. I would recommend downloading the data in UINT16 which is the native Sample Type for Sentinel-2 L2A data. You can read more about that here.
In addition, I would recommend also reading this blog post by my colleague, Maxim Lamare which explains the importance of Sample Types.
Lastly, instead of EO Browser, have you thought of using Sentinel Hub Process API to fetch your data? You can do this programatically with Python or in Request Builder. Here you will be able to specify the same projection as the Scihub data.
I will continue to investigate and see if we can find a solution for you.