The invention discloses a grabbing mechanism for a robot. The grabbing mechanism comprises a palm part, a near end knuckle, a far end knuckle, a finger bending tendon rope and a finger extending tendon rope, wherein the near end knuckle includes a first near end knuckle and a second near end knuckle pivoted to the palm part; the far end knuckle includes a first far end knuckle and a second far end knuckle pivoted to the corresponding near end knuckles; the finger bending tendon rope includes a first finger bending tendon rope and a second finger bending tendon rope connected to the corresponding far end knuckles by far ends; the finger extending tendon rope includes a first finger extending tendon rope and a second finger extending tendon rope connected to the palm part by near ends and connected to the corresponding far end knuckles by far ends; in actual grabbing process, when the grabbing mechanism dose not touch an object, the near end knuckles and the far end knuckles do not move corresponding to each other until the near end knuckles or the far end knuckles touch the object; when the near end knuckles touch the object, the far end knuckles rotate to the object corresponding to the near end knuckles in a pivoted manner; and when the far end knuckles firstly touch the object, the near end knuckles and the far end knuckles do not move corresponding to each other.