In order to study the influence of the mechanical performance of a unidirectional through precast concrete floor, a group of 3 unidirectional through precast slab specimens were designed to compare the bending performance with that of cast-in-place floor slabs. By investigating the characteristics of the slab failure form, mid-span deflection change, stress change of the reinforcement in the slab, and strain change of the concrete at the bottom of the slab, the following conclusions were drawn: No obvious brittle failure was observed during the test, and the bending resistance of each test plate was good. The crack development of the test board shows that the mechanical performance of the precast wood fiber concrete floor is similar to that of cast-in-place solid floor, and the crack distribution is more uniform. The ultimate bearing capacity of all cavity plates is higher than that of 100 mm thick core plate, and the ultimate bearing capacity of 100 mm thick core plate is increased by about 46.1%.