Randomized controlled trials (RCTs) are a cornerstone of high-quality medical research. Rigorously conducting RCTs in primary care settings significantly improves evidence generation, validates findings, optimizes clinical guidelines, and translates research into practice. However, the design and implementation of community-based RCTs in the fields of primary care and general practice are limited by practice, methodology, and resources. This article aims to introduce and discuss the design principles, implementation strategies, key procedures of community-based RCTs, as well as their precautions and limitations. By analyzing the design and implementation of trials conducted in China and internationally, this article informs primary care and general practice researchers on how to rigorously conduct randomized controlled trials.