把下面的代码粘贴到SQL Query Analyzer（查询分析器）里执行即可（注意修改红色部分的3个参数）：

SET NOCOUNT ON
DECLARE @LogicalFileName sysname,
@MaxMinutes INT,
@NewSize INT

USE Dicky  --需要缩小日志的数据库名
SELECT @LogicalFileName = ''''Dicky_Log'''',  --日志文件的逻辑名，非物理文件名
@MaxMinutes = 10, -- Limit on time allowed to wrap log.
@NewSize = 2 --需要重新设定的日志文件的大小(单位:M)，此值必须小于原先文件大小

-- Setup / initialize
DECLARE @OriginalSize int
SELECT @OriginalSize = size
FROM sysfiles
WHERE name = @LogicalFileName
SELECT ''''Original Size of '''' + db_name() + '''' LOG is '''' +
CONVERT(VARCHAR(30),@OriginalSize) + '''' 8K pages or '''' +
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + ''''MB''''
FROM sysfiles
WHERE name = @LogicalFileName
CREATE TABLE DummyTrans
(DummyColumn char (8000) not null)

DECLARE @Counter INT,
@StartTime DATETIME,
@TruncLog VARCHAR(255)
SELECT @StartTime = GETDATE(),
@TruncLog = ''''BACKUP LOG '''' + db_name() + '''' WITH TRUNCATE_ONLY''''

DBCC SHRINKFILE (@LogicalFileName, @NewSize)
EXEC (@TruncLog)
-- Wrap the log if necessary.
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName)
AND (@OriginalSize * 8 /1024) > @NewSize
BEGIN -- Outer loop.
SELECT @Counter = 0
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))
BEGIN -- update
INSERT DummyTrans VALUES (''''Fill Log'''')
DELETE DummyTrans
SELECT @Counter = @Counter + 1
END
EXEC (@TruncLog)
END
SELECT ''''Final Size of '''' + db_name() + '''' LOG is '''' +
CONVERT(VARCHAR(30),size) + '''' 8K pages or '''' +
CONVERT(VARCHAR(30),(size*8/1024)) + ''''MB''''
FROM sysfiles
WHERE name = @LogicalFileName
DROP TABLE DummyTrans
SET NOCOUNT OFF