The utility model discloses an assembled safety platform based on a precast beam plate, which comprises a safety platform sidewalk and a movable pedestrian safety ladder arranged at one end of the safety platform sidewalk, and the safety platform sidewalk is formed by splicing a plurality of safety platform units which are sequentially arranged on a rear rib of a side die of the precast beam plate; wherein each safety platform unit comprises a pedal plate, an inner side guardrail welded to the edge of the inner side of the pedal plate, an outer side guardrail welded to the edge of the outer side of the pedal plate and a fixing frame horizontally arranged between the edge of the inner side of the pedal plate and a rear rib of a side mold of the prefabricated beam plate, hook units are welded to the inner side guardrail, and dense steel wire nets are distributed in the outer side guardrail. According to the splicing type safety platform based on the prefabricated beam plate, the personalsafety of workers in the construction process can be guaranteed, the construction quality and efficiency are improved, operation is easy, use is rapid and convenient, and the splicing type safety platform can be widely applied and popularized in engineering practice.