Anyways to insert multiple rows into sqlserver?

Question

 Anyways to insert multiple rows into sqlserver?

I am dealing with some sort of daily data and I need to parsing those data out from txt files and save those into sqlserverdatabase. What I did right now is just to read from those txts line by line and insert into tables. But the problem is, for each single day, it has more than 2 million rows which is really time consuming. 

I am just wondering, are there any ways I can make it more efficient? Any suggestion is welcome.

Ps. I am using C#

Thanks,