Unmanned transportation systems are constantly being popularized and promoted in port freight transportation， and their front-end environmental perception technology is the foundation for efficient operation of unmanned transportation systems. Due to the late start of automatic port freight transportation in China， how to integrate the latest advanced autonomous driving technology into unmanned port freight transportation systems is currently an important issue. This paper provides a comprehensive review of environmental perception technology in port automatic freight systems， and summarizes the composition， main technical challenges， hardware and software algorithms of the perception system for unmanned freight transportation in ports. Further， it looks forward to the future trend of environmental perception technology for automatic freight transportation in ports， providing reference for the intelligent upgrading of port freight transportation.