Abstract: The discrete ordinates-discontinuous finite element method for 3D neutron transport equation was presented. Energy variables were dispersed by multi-group approximation, direction variables by discrete ordinates method, and space variables by discontinuous finite element method (DFEM). The solution order of finite element meshes for each discrete direction and the solution method of several matrixes for DFEM equation were investigated. Hence, the 3D neutron transport code TetTran1.0 based on unstructured meshes was developed. The numerical results of some benchmarks show that the code has high computational accuracy.