The present application discloses a protection apparatus. The protection apparatus is connected to an end effector which includes a casting, a fixed part fixed to the casting, a rotational part rotatable relative to the fixed part, and a sealing part provided in a circumference of the rotational part. The protection apparatus comprises a cover, an annular elastically deformable sealing member and a fixing member; the sealing member is partly accommodated between the cover and the rotational part; the cover is attached to the fixed part, the cover being adapted to cover the exterior of the fixed part by the fixing member, so as to prevent the fixed part from being exposed to an exterior; and the cover and the sealing member are configured to jointly cover the sealing part to prevent the sealing part from being exposed to an exterior. The present invention also provides an end effector and a robot.