To obtain titanium alloy porous structures with good mechanical properties and high permeability, a trade-off between the porosity of the porous structure and its strength needs to be maintained. Taking human knee tibial prosthesis as the research object, firstly, according to the stress state of the tibia, topology optimization is used to design and reconstruct the compressive and shear cell structures (TO-P1, TO-P2, TO-S1, TO-S2) under different loading conditions, and several common basic cell structures (BCC, FCC, RDC, DCC) are studied and compared; secondly, by performing different types of porous titanium alloys for compression and shear performance simulation, to research the mechanical properties of porous titanium alloys with different topologies regarding compression and shear resistance, and to verify the validity of the simulation analysis by forming porous titanium alloy compression specimens with SLM technology; finally, four porous titanium alloys with better mechanical properties were chosen for permeability analysis. The results show that the TO-S2 structure has the best compressive, shear mechanical properties and permeability, suitable for porous structures of compression-shear load type implants.