The invention discloses a sliding-type top cover plate of a low voltage switch cabinet. The sliding-type top cover plate of the low voltage switch cabinet is mainly composed of two cover plate bodies which are the fixed cover plate body and the movable cover plate body. The two cover plate bodies are movably connected together through rollers and guiding rails to form the whole sliding-type top cover plate. The two outer side edges of the fixed cover plate body are fixedly provided with the two guiding rails respectively in the mode that screws penetrate through guiding rail fixing holes. The two inner side edges of the movable cover plate body are provided with the fixed rollers respectively. Bearings roll inside guiding rail guiding grooves to form a pluggable sliding-type mechanism. According to the sliding-type top cover plate, the top structure of the low voltage switch cabinet is optimized, using is more convenient, bus installation and other operations can be carried out only by opening the top cover plate in a sliding mode, the defect that a bus cannot be plugged in a penetrating mode or installed when a switching room is small in space is overcome, and various site installation conditions can be met.