The invention discloses a fin part doping method and a manufacturing method for a fin type field effect transistor. For the fin part doping method, a bottom diffusion barrier layer is arranged on the surface of a semiconductor substrate between fin parts in a thermal annealing process, so that diffusion of P type ions in a P type ion diffusion source, and N type ions in an N type ion diffusion source on the substrate to the semiconductor substrate can be prevented; therefore, the source region/drain region in each fin type field effect transistor in the same well region or in adjacent well regions cannot be conducted, so that crosstalk in reading and writing processes can be avoided, and the performance of the fin type field effect transistor is improved; and in addition, by virtue of the bottom diffusion barrier layer, the N type ions in the N type ion diffusion source on the P type ion diffusion source cannot diffuse to the substrate, or the P type ions in the P type ion diffusion source on the N type ion diffusion source cannot diffuse to the substrate, so that the upper layer ion diffusion source does no need to be removed, and processes can be omitted.