Porous titanium scaffolds with high porosity and connected macropores are fabricated by adding zirconium acetate to control the ice crystal growth during freeze casting. The influences of zirconium acetate additives on the phase composition, pore structure, and mechanical properties of porous titanium are studied. As modified by zirconium acetate, the X‐ray diffraction peaks of titanium moves to a smaller angle, and the zirconium is evenly distributed on the titanium matrix. With the increase in the concentration of zirconium from 0 to 60 g L−1, the pore morphology of porous titanium changes from typical lamellar to the honeycomb, the pore size distribution becomes wider. The average pore size and porosity increases from 44 ± 11 to 126 ± 35 μm and from 46.4 ± 1.3 to 59.1 ± 1.3%, respectively. As the concentration of zirconium acetate is 40 g L−1, the porosity and the pore size of the porous titanium scaffolds are comparable with those modified by 10 g L−1 zirconium acetate, but the compressive strength is 2.3 times higher. Zirconium acetate as an additive has an excellent performance in optimizing the pore structure and mechanical properties of water‐based freeze‐cast porous titanium.