[Objective] Through a case study in quantitative evaluation of benefits from comprehensive watershed harness of Yao'an small watershed of Qingyuan City in Guangdong Province, we expected that some references for the watershed harness and benefit evaluation. [Methods] According to the disaster characteristics of small watershed in the province, the harness destination and actual situation of Yao'an small watershed, 4 benefit types(flood protection and disaster reduction, soil and water conservation and ecological, economic and social benefit ) and 21 indices were chosen to evaluate the benefits from comprehensive harness of watershed. Methods of data standardization, fuzzy comprehensive evaluation model and analytic hierarchy process were used. [Results] (1) The indices system and evaluation model presented well the comprehensive benefit of soil and water conservation of small watershed, and were suitable in the region of Guangdong Province. (2) The comprehensive benefit and the above four benefit items were all improved with different percentages from 2007 to 2013 in Yao'an small watershed, among them, the disaster reduction benefits from flood protection and economic benefit were remarkable. [Conclusion] The indices and method used in quantitative benefit evaluation for comprehensive control were practical and suitable in the watershed of Guangdong Province. After comprehensive harness been conducted, the withstanding ability to disaster was signally enhanced and the situation of soil loss was moderated.