Boron neutron capture therapy(BNCT) is a promising approach for treatment of some malignant tumors, which can not be cured by conventional therapies, such as glioblastoma multiforme and melanoma. This paper mainly investigated the choice of the neutron source used for BNCT. Based on the analysis of the clinical requirements of BNCT and the characteristics of various neutron generators, the concept of using radiation frequency quadrupole(RFQ) as the preferred neutron source was brought forward. Since the epithermal neutron emits from the 7Li(p,n)7Be near threshold reaction has low energy and small angular, 1.9 MeV was chosen as the final energy of the RFQ suitable for BNCT. In order to get enough neutron flux the induced proton current should be 100 mA. After choosing the basic parameters,