select pr.name,p.*
from sys.procedures pr 
inner join sys.parameters p on pr.object_id = p.object_id

并加入类型…

select pr.name,p.*,t.name,t.max_length
from sys.procedures pr 
inner join sys.parameters p on pr.object_id = p.object_id
inner join sys.types t on p.system_type_id = t.system_type_id