The Pamatangan, an Amis indigenous tribe, faces flood risk as it is located on the Da-an riverbank in Taoyuan City. Over the last decade, the government has gradually built hardware construction and applied a flood management strategy to mitigate flood risk. Understanding residents’ disaster information transmission and evacuation decision-making process could fundamentally reduce their disaster exposure. Semi-structured interviews were conducted to explore the relationship between residents’ disaster information transmission and their evacuation decision-making process. The results showed that Typhoon Herb caused local floods and transformed information transmission from "culture-based reciprocal communal communication" to "command-oriented unilateral order beyond community". Further, residents’ evacuation behavior transitioned from "consensus-based collective action" to "obedience to command for the right of abode". Consequently, increasing positive risk communication between the public sector and the tribe and bolstering consensus within the tribe to foster residents’ autonomous evacuation decision-making would ensure sustainability.