create table A(id int,psort int) 
insert into A select 10,0 
insert into A select 11,0 
insert into A select 13,0 

declare @IDS varchar(20),@PSORTS varchar(20),@sql VARCHAR(1000)
SELECT @IDS='55,44,10,13,15,90',@PSORTS='1,2,3,4,5,2'

create table #t(id int identity(1,1),c2 int)
select @sql= 'select  '+replace(@psorts, ',', ' union all select  ') 
insert into #t(c2) exec(@sql) 


update a set a.psort=c2 from a inner join #t t
    on     len(@ids)-len(replace(@ids,',',''))+1 
        -len(stuff(@ids,1,charindex(','+rtrim(a.id)+',',','+@ids+',')+1,''))
        +len(replace(stuff(@ids,1,charindex(','+rtrim(a.id)+',',','+@ids+',')+1,''),',','')) 
        =t.id
    where charindex(','+rtrim(a.id)+',',','+@ids+',')>0

select * from a

drop table A,#t

------解决方案--------------------
SQL code
create procedure updateTableA
    @idS varchar(100),
    @psortS varchar(100) 
AS
BEGIN
    Declare @spot1 int, @spot2 int, @id varchar(100), @psort varchar(100), @sql varchar(200)
    WHILE @idS <> '' AND @psortS <> ''
    Begin
        SET @spot1 = Charindex(',',  @idS)
        SET @spot2 = Charindex(',', @psortS)
        if @spot1 > 0 AND @spot2 > 0
        Begin
            SET @id = cast(left(@idS, @spot1-1) as int)
            SET @psort = cast(left(@psortS, @spot2-1) as int)
            set @idS = right(@idS, len(@idS)-@spot1)
            set @psortS = right(@psortS, len(@psortS)-@spot2)
        END
        ELSE
        Begin
            SET @id = cast(@idS as int)
            set @psort = cast(@psortS as int)
            set @idS = ''
            set @psortS = ''
        END
        SET @sql = 'UPDATE A SET psort = ' + @psort + ' WHERE id= ' + @id
        exec(@sql)
    END
End


drop table A

create table A
(id int, psort int)
insert into A select 10,0 
insert into A select 11,0 
insert into A select 13,0 
GO

declare @idS varchar(100),@PSORTS varchar(100)
set @idS= '10,13'
set @PSORTS = '2,5'
exec updateTableA @idS, @Psorts 

select * from A