The foreseeable global animal production pressure has triggered people to search for sustainable novel feed resources. As the most abundant species in the world, insects are considered to be an alternative feed source. This review is to give comprehensive analysis of the insect as animal feed. In recent years, insect feed has been used in poultry, livestock production, aquaculture and pets. Positive impacts of using insect as feed source include nutritional enrichment, economic benefits and environmental merits. Also, barriers of using insects as feed related to animal products evaluation, insect breeding scale, consumer acceptance and legislation. This paper will be helpful in laying the foundation for the in-depth development and utilization of insect feed resources.