Disclosed are a method and device for selecting resources, capable of achieving selection of resources under a condition of insufficient available resources or no available resources. The method comprises that: a terminal device determines that the proportion of the number of available resources in a candidate resource set to the total number of resources in the candidate resource set is less than a preset proportion, or the number of the available resources in the candidate resource set is less than a preset value; the terminal device determines a first available resource set in the candidate resource set; and the terminal device determines a resource for data transmission in the first available resource set.