直接将以下代码复制到SQL中运行即可，记得一定先指定数据库，否则操作失误可无法恢复的。

declare @table varchar(600)

while (select count(*) from sysobjects where type='u')>=1
 begin
  set @table=(select top 1 name from sysobjects where type='u')
  set @table='drop table '+@table
  exec(@table)
 end

select  name,type from sysobjects where type='u'