he didn't dare to draw a deep breath

简单解释呢，draw a breath深吸气，那就是个固定词组！没有为什么。
整句就是“他不敢大口呼吸”。

draw的意思很多:
draw
draw
AHD:[drô]
D.J.[dr%8]
K.K.[dr%]
v.（动词）
drew[dr›] drawn[drôn] draw.ing， draws
v.tr.（及物动词）
To cause to move after or toward one by applying continuous force; drag:
拉：持续用力使之向或随某人或某物运动；拉：
drew the chair closer to the table; a team of horses drawing a wagon.See Synonyms at pull
把椅子拉近桌子；拉车的一队马车参见 pull
To cause to move in a given direction or to a given position, as by leading:
拉向：（引导而）使向给定的方向或位置移动：
The teacher drew the children into the room to see the decorations.
老师带领着孩子到房间里去看布置
To move or pull so as to cover or uncover something:
拉起来：移动或拉动以盖上或暴露出某物：
draw the curtains.
拉上窗帘
To cause to flow forth:
使流出：
a pump drawing water; a blow that drew blood.
抽水的水泵；打出血的一击
To suck or take in (air, for example); inhale.
吮或吸入（如空气）
To require (a specified depth of wa