The utility model provides a low -speed magnetic suspension roof beam among precast reinforced concrete has such characteristic, include: magnetcisuspension fuliang body is the rectangle, and inside cavity, quantity are two, parallel arrangement, a plurality of linking beam evenly set up in the middle of two magnetcisuspension fuliang bodies, and both ends are connected with two magnetcisuspension fuliang bodies respectively, the concrete plummer is fixed at magnetcisuspension fuliang body top, H shaped steel sleeper is fixed on the concrete plummer, F rail tablet sets up the both sides at H shaped steel sleeper, sparse platform sets up between two magnetcisuspension fuliang bodies, and the lower extreme is fixed on the concrete plummer, the forceful electric power support sets up the both sides at sparse platform, the light current support sets up the both sides at sparse platform, the support rail platform sets up the both sides at magnetcisuspension fuliang body, and the steel sleeper, set up the both sides at the support rail platform.