Referring to the performance parameters of an advanced three-stage booster, this paper tries to design a new ultra-highly loaded booster with only one stage to replace the original one by applying a new concept of diffusion blade profile with large camber and low flow losses. With the index of performance parameters at design point, an optimization method based on genetic algorithm is used to optimize the rotor blade and stator blade, and the surge margin of the booster is further improved by change the blade stacking line of the rotor blade. It shows that 3-D optimization method can improve the performance parameters at the design point highly. For ultra-highly loaded rotor, forward sweep at rotor blade tip can make the load of the blade move downstream and decrease the load of the leading edge which can increase the tolerance range of attack angle and improve the surge margin of the booster stage. At the design point, the newly designed booster has nearly the same total pressure ratio and surge margin as the original booster and exhibits higher efficiency than the original booster. It can also match well with the transition channel, which verifies the feasibility of the design method.