--测试数据
declare @table1 table(col1 varchar(10), col2 varbinary(20))
insert @table1
select 'a',cast('11aaa22bb' as varbinary)
union all select 'b',cast('22aaabbaaa33' as varbinary)
--更新
update @table1 set col2=cast(replace(col2,'aaa','bbb') as varbinary)
where charindex('aaa',col2)>0
--更新结果
select *,cast(col2 as varchar) from @table1
/*--测试结果
col1 col2
---------- ------------------------------------------ ------------------
a 0x313162626232326262 11bbb22bb
b 0x323262626262626262623333 22bbbbbbbb33