The invention discloses a protective device for protecting pins of an electrolytic capacitor. The protective device comprises two protective sleeves with elastic deformation and an external member, wherein the external member is used for being suspended on an electrolytic capacitor body; an accommodating slot for accommodating each pin is formed in each protective sleeve; the accommodating slots are arranged along the axial directions of the protective sleeves; a leaf spring is arranged between the two protective sleeves; and two ends of the external member are hinged with the opposite side walls of the two protective sleeves respectively. According to the protective device, two pins of the electrolytic capacitor are inserted into the two accommodating slots of the protective sleeves respectively, so that the risk that the two pins of the electrolytic capacitor are bent in the transport process or broken down in an electric field environment is avoided. The external member is suspended on the electrolytic capacitor body, so that, on one hand, connection of the protective sleeves and the electrolytic capacitor body is reinforced and slipping is avoided; and on the other hand, the problem that the pins are distorted due to a relative motion of the electrolytic capacitor body and the protective sleeves is solved.