Purchasing food from community-level grassroots organizations was a novel and unforgettable experience for Wuhan residents during the COVID-19 lockdown, but little attention was paid to it. The study examined the relationship between community-level grassroots organizations and household food insecurity based on an online survey of household food insecurity in Wuhan in March 2020. The study found that problems in all three domains of food insecurity including food anxiety, food quality and food quantity existed but were uneven. The COVID-19 epidemic affected household food quality the most, while it had the least impact on household food quantity. Community-level grassroots organizations played an important role in promoting food security including reducing worries about food supply and providing enough food intake, but did not ensure households had adequate food quality due to increasing food prices, fewer varieties of food and decreased food freshness. Compared to other grassroots organizations, the community committee had actually become an extension of the government to run administrative grassroots affairs before the epidemic, so its tight relationship with local government made it become the major grassroots power in ensuring household food security at the residential community level.