Titanium and its alloys with low density, high strength, good corrosion resistance, good biocompatibility and so on are widely used in the fields of aerospace, marine engineering, petrochemical industry, biomedical, electronic engineering etc., and it is a very important strategic metal after steel and aluminum, known as the "third metal", "space metal" and "marine metal". Porous titanium is a kind of structural and functional integrated material with dual properties of both porous material and titanium, and it is also an indispensable key supporting material in modern high-tech field. The paper reviewed the preparation processes of porous titanium, including powder metallurgy techniques (loose sintering, die compaction process, space holder method, slurry forming technique and additive manufacturing process), and chemical synthesis (reaction sintering, combustion synthesis, calciothermic reduction, dealloying), and the application status of porous titanium was briefly described in the fields of biomedical, filtration & separation, and electrochemistry, etc. Pore structure of porous titanium is the key factor affecting its applied properties, so it should be strengthened to control accurately the pore structure and to study its coupling mechanism with the applied conditions. Furthermore, the design and preparation technology of porous titanium with ultra-lightweight and ultra-high strength should be developed through the interdisciplinarity of materials, mechanics and mathematics.