1、把mdf文件和ldf文件拷贝到数据库的默认路径C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA里；
2、在sqlserver里新建个查询，执行下面代码；

USE master;
GO
CREATE DATABASE NewFile
ON (FILENAME = 'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\File.mdf'),
(FILENAME = 'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\File_log.ldf')
FOR ATTACH;
GO