data have;
input type $14. count;
datalines;
critical      1
critical      2
non-critical  3
half-critical 4
half-critical 5
half-critical 6
non-critical  7
non-critical  8
critical      9
critical      10
half-critical 11
half-critical 12
;
run;

/****method 1:SQL****/
proc sql;
create table want as
select distinct type,
       sum(count) as total
from have
group by 1
order by 2
;
quit;

/***method 2:data step****/

proc sort data=have;
by type;
run;

data want2 /*(drop=count)*/;
set have;
by type;
total+count;
if first.type then total=count;
*if last.type;
run;


both methods have their pros and cons

是这样的，其实critical，non-critical不是data_type的值，只是一个format，值是不一样的。我想按照这种format来分类累加

I don't think the formats matter. You can still go ahead and try it.