The invention discloses an analog system and a flow resistance computing method for determining urban ecological river flow resistance. The analog system comprises an urban ecological river analog system and a river flow resistance measuring system. The urban ecological river analog system comprises an analog urban ecological river and an analog vegetational zone. The analog vegetational zone is arranged in the analog urban ecological river. By establishing the urban ecological river analog system and the river flow resistance measuring system and through combination of hydraulics resistance theoretical knowledge, flow resistance under different hydraulic conditions is obtained, the flow resistance is computed through the moment balance principle, the established analog system is simple and practical, the blank of the research of urban ecological river flow resistance is filled up, and technical support is provided for planning and design of an urban ecological river.