To apply the UHPC elements in building construction， this paper proposes a fully prefabricated spliced channel-shaped section UHPC beam. The beam is designed with bolt ribs that have through bolt holes. Two ribbed channel-shaped section beams are installed through forward and reverse splicing to form two kinds of fully assembled combination connection modes of beams and columns， i.e.， I-type and box-type. To study the bending and shear resistance of the spliced UHPC beams， three beam bending experiments were conducted， including cast-in-place I-beam， box-type spliced beam， and I-type spliced beam. Through the bending test， it was found that the stiffness of the spliced beam was slightly higher than that of the cast-in-place beam， and the bending capacity of the I-type spliced beam was higher than that of the cast-in-place beam， thus proving that the bending resistance of the UHPC spliced beam was better than that of the UHPC cast-in-place beam. To study the shear resistance of the I-type spliced beams， shear tests of nine I-type spliced beams were completed by setting different shear-to-span ratios and stirrup spacing through orthogonal test design. The cracking load， failure loads， deformation， and crack distribution laws were obtained. The shear test revealed that， with the same stirrup spacing， the failure mode of the I-type spliced beam was diagonal-compression and shear-compression failure， respectively， as the shear-span ratio was increased from 1 to 2 or 3. For the beam with stirrups and the same stirrup spacing， the larger the shear-span ratio， the lower the load-carrying capacity and the better the ductility of the channel-spliced beam. Moreover， the stirrups in the beams had a restraining effect on the development of the main cracks.