一、
need to do 需要做某事
need doing 是需要被做有被动的意思
如;I need to wash my clothes.
My clothes need washing.
need doing = need to be done
I need to mend my bike.
My bike needs mending
二、
need to do 一般主语是人
need doing 一般主语是物
三、
need to do sth 是必须做某事 但还没做过 、
need doing sth 是 需要做某事 已经做完了.