修改语句delete from tb_cust_property where cust_id in(SELECT cp.cust_id FROM tb_cust_property cp left join tb_cust_personal_info cpi on cp.cust_id = cpi.cust_id where cp.cust_flag= '1' and sex is null and cust_score is not null group by level_time desc)

你可以将语句修改为以下形式：

DELETE FROM tb_cust_property
WHERE cust_id IN (
    SELECT cp.cust_id
    FROM tb_cust_property cp
    LEFT JOIN tb_cust_personal_info cpi ON cp.cust_id = cpi.cust_id
    WHERE cp.cust_flag = '1' AND cpi.sex IS NULL AND cp.cust_score IS NOT NULL
    GROUP BY cp.level_time DESC
)

请注意，我对语句进行了格式化，以提高可读性。如果有其他要求，请告诉我。