Abstract: The accuracy and efficiency of core physics calculation have a great impact on the safety of nuclear reactors. As reactor cores get more and more complex, diffusion theory presents low accuracy. Various transport methods are developed and studied. The even-parity discrete ordinates method(EPSN) needs less storage and less computing time due to a reduction in angular domain of one-half compared to the first-order transport equations. The new high-efficiency even-parity discrete ordinates(HEPSN) method is proposed based on optimizing the EPSN method. It is worth noting that HEPSN method only solves one-eighth of the angular domain. HEPSN method appears to have no negative flux, be easy to obtain consistent diffusion synthetic acceleration and have uncoupled reflective boundary conditions. The accuracy of HEPSN method for critical calculation is verified by TAKEDA benchmarks. The results show that the accuracy of HEPSN method is higher than diffusion theory and the computing time and the computer memory are less than EPSN method. HEPSN method has the potential to be applied to the calculations of large reactor cores.