As the “peripheral nerve” in river chief organization system, grassroots river chiefs play a fundamental and key role in promoting the overall establishment of the river chief system. Therefore, it is of great strategic significance to construct the competency model of grassroots river chiefs for standardizing the work requirements, improving their ability to perform their duties and comprehensively implementing the tasks of the river chief system. The behavioral event interview method was used to interview 22 grassroots river chiefs, and the interview content was analyzed with the software ATLAS Based on the grounded theory, an initial competency model of grassroots river chiefs, including five dimensions and 23 competency elements, was constructed through open coding, principal axis coding and selective coding. The initial competency model of grassroots river chiefs was tested and modified through questionnaire survey into the final grassroots river chief competency model, which is composed of five dimensions: river and lake management ability, collaboration ability, stress resistance, professional quality and personality traits, and passed the reliability and validity test. The competency elements of grassroots river chiefs should be taken as an important basis for evaluation, assessment and training of grassroots river chiefs, as well as an important guidance for the improvement of the policy of the river chief system, so as to make the system better serve practice and promote the transformation of river chief system from “famous” to “practical”.