This paper presents an unfactored efficient algorithm for 3-D Euler equationsbased on the implicit flux-splitting and the line Gauss-Seidel iteration. In the algorithm the explicit terms on the right side of the discretization equation are treated in second order accuracy and to solve the implicit discretization equation one back-and-forth sweep in the main flow direction is taken and an alternating direction line G-S interation is carried out in the other two directions. The numerical calculations of 3-D transonic cascade inviscid blow tave shown that the algorithm has a quite high convergent rate.