First , you need to add column in your table with varbinary datatype.
Then you have to convert file in byte array
string sPath ="";
byte[] ydata = null;
FileInfo fInfo = new FileInfo(sPath);
long lNumBytes = fInfo.Length;
FileStream fStream = new FileStream(sPath, FileMode.Open, FileAccess.Read);
BinaryReader br = new BinaryReader(fStream);
ydata = br.ReadBytes((int)lNumBytes);
return ydata;
You can use this generated byte array as a parameter value in Insert statement.