thanks, but , sorry, this answer isn't the answer I'm looking for . maybe my question is not very clear.

the true requirements like this:

CREATE TABLE T_TEST
(
V1 VARCHAR2(1) NOT NULL,
V2 VARCHAR2(1) NOT NULL
)

create or replace procedure p_test (pi_v1 in varchar2,
pi_v2 in varchar2
) is
begin

FOR L IN (
SELECT COLUMN_NAME, NULLABLE
FROM SYS.USER_TAB_COLUMNS T1, SYS.USER_TAB_COMMENTS T2
WHERE T1.TABLE_NAME=UPPER('T_TEST') AND T1.TABLE_NAME = T2.table_name AND T1.NULLABLE = 'N') LOOP
IF PKG_PARAMUTL.ASSERTNULL(
'PI_'||L.COLUMN_NAME --here I　want use this param name to get param value, so I can write a general check program
)

THEN
HERE WILL DO SOMETHING
END IF;

END LOOP;

end;

create or replace procedure p_test (
  p_parm_vals in array_as_per_before
) is 
begin 

FOR L IN ( 
  SELECT COLUMN_NAME, NULLABLE 
  FROM SYS.USER_TAB_COLUMNS T1, SYS.USER_TAB_COMMENTS T2 
  WHERE T1.TABLE_NAME=UPPER('T_TEST') AND T1.TABLE_NAME = T2.table_name AND T1.NULLABLE = 'N') LOOP 

  IF PKG_PARAMUTL.ASSERTNULL( 
    p_parm_vals(L.COLUMN_NAME)
  ) 

THEN 
  HERE WILL DO SOMETHING 
END IF; 

create or replace package PKG_PARAMUTL is

-- Author : LIUGR
-- Created : 2016/2/22 15:31:47
-- Purpose : 参数设置可用到的一些公共基础

-- Public type declarations
--type <TypeName> is <Datatype>;
NULL_EXCEPTION EXCEPTION;

/**//*将名称与用于触发器中的错误号码关联起来*/
---RAISE_APPLICATION_ERROR error_number -20000 到 -20999
PRAGMA EXCEPTION_INIT(NULL_EXCEPTION, -20991);


-- Public constant declarations
--<ConstantName> constant <Datatype> := <Value>;

-- Public variable declarations
--<VariableName> <Datatype>;

-- Public function and procedure declarations
--function <FunctionName>(<Parameter> <Datatype>) return <Datatype>;

FUNCTION ASSERTNULL(PI_PARAMVALUE IN ANYDATA) RETURN BOOLEAN;

FUNCTION getanydata(v_data IN anyData) RETURN VARCHAR2;

end PKG_PARAMUTL;


create or replace package body PKG_PARAMUTL is

-- Private type declarations
--type <TypeName> is <Datatype>;

-- Private constant declarations
--<ConstantName> constant <Datatype> := <Value>;

-- Private variable declarations
--<VariableName> <Datatype>;

-- Function and procedure implementations
FUNCTION getanydata(v_data IN anyData)
RETURN VARCHAR2 IS
v_num NUMBER;
v_date DATE;
v_re_data VARCHAR2(4000);
BEGIN
CASE v_data.gettypeName
WHEN 'SYS.NUMBER' THEN
IF (v_data.getNumber(v_num) = dbms_types.success) THEN
v_re_data := v_num;
END IF;
WHEN 'SYS.DATE' THEN
IF (v_data.getDate(v_date) = dbms_types.success) THEN
v_re_data := to_char(v_date,'yyyy-mm-dd hh24:mi:ss');
END IF;
WHEN 'SYS.VARCHAR2' THEN
IF (v_data.getVarchar2(v_re_data) = dbms_types.success) THEN
NULL;
END IF;
ELSE
v_re_data := 'not number or date or varchar2';
END CASE;

RETURN v_re_data;
END getanydata;

FUNCTION ASSERTNULL(PI_PARAMVALUE IN ANYDATA) RETURN BOOLEAN
is
begin
return getanydata(PI_PARAMVALUE) is null ;
end ASSERTNULL;


begin
-- Initialization
--<Statement>;
NULL;
end PKG_PARAMUTL;

Thanks for your supplement, this is very helpful .
I feel depressed that The dynamic referencing does not exist in PL/SQL.