Sr3YCo4O10.5+δ polycrystalline bulks were prepared by the solid state reaction of 7 processes with different sintering temperatures (950~1 180 ℃), sintering time and sintering times. Based on thermal analysis, XRD and SEM, order phase transition and optimal sintering process (1 180 ℃/24 h+1 180 ℃/24 h) were determined, then electrical magnetic properties of polycrystals were inverstigated. The results show that the tetragonal Sr3YCo4O10.5 fully crystallized at 964 ℃ and formed the ordering Sr3YCo4O10.5+δ by absorbs oxygen (δ) at 1 042 ℃. Samples sintered at 1 100 ℃ and 1 180 ℃ show superstructure peaks of (103) and (215), which verifies the order of polycrystalline structure. The bulks exhibit semiconductor behavior, secondary sintering improve the lattice integrity, grain growth and resistivity is only 0.06 Ω·cm at 300 K, Curie temperature (Tc)~335 K. Hopkinson peak on the zero field colded (ZFC) curve from the fact that the frozen magnetic moments at low temperature turn to the direction of the magnetic field as the temperature rises, the magnetization reaches the maximum at 298 K, and then decreases under the thermal disturbance. Room temperature ferromagnetism originates from the eg orbitals ordering of the middle spin or high spin state Co3+ caused by the ordered structure.