With the rapid growth of communication capacity of optical networks, integrating discrete optical devices into a single chip to reduce footprint and cost becomes a development of optoelectronic devices. Photonic integrated circuit has many advantages such as small footprint, low power consumption and light weight, and it is a key technology for future broad-bandwidth optical networks to solve the problems of large energy consumption, large volume and small capacity. We review three kinds of large-scale photonic integration technologies which are based on multi-project wafer flow sheets, including silicon-based photonic integration technology, Ⅲ-Ⅴ indium phosphide integration technology and TriPleX integration technology which consists of multilayer waveguides of silicon nitride and silicon oxide. Three foundries supporting multi-project wafer sheet photonic integration technologies are introduced, and some chip examples realized by these foundries are presented. The comparison of technology parameters among different foundries is carried out.