3D printing is a rapid prototyping technology based on an additive process. Stereolithography (SLA) as a mature 3D printing technology has been widely applied in industrial manufacture. SLA is the process of single-photon polymerization (SPP)

and its resolution is controlled by the optical diffraction limit

which cannot meet the requirement for three dimensional micro/nanostructures with high resolution. Unlike SLA

3D printing technology based on two-photon polymerization (TPP) induced by a near-infrared femtosecond laser can fabricate arbitrary and ultraprecise 3D microstructures with high resolution not only on the microscopic scale but also on the nanoscale. In this review

the principles of two-photon absorption and TPP were concisely explained. The development of TPP mainly focusing on TPP resolution and TPP initiators were introduced as well as the applications of 3D printing technology based on TPP. Finally

the perspective of 3D printing technology based on TPP was proposed.