<p>With the increasing of inlet temperature and pressure of the heavy-duty gas turbine, the flow conditions in the turbine become more complicated, and the aerodynamic loss inside the cascade also increases. This problem is particularly serious in small aspect ratio blades. How to reduce the aerodynamic loss inside the cascade channel becomes quite urgent now. Based on previous studies, it can be seen that the positively curved blade can reduce the secondary flow loss at the blade end, but it will increase the profile loss, while the negatively curved blade behaves just in the opposite way of the positively curved blade. Therefore, this paper proposes a positively curved blade with negatively curving at blade end, and this design can help to reduce the negative effect of the positive curving modification on the middle of the blade. In this paper, the last stage of the GE-E3 high-pressure turbine is taken as the research object, and the composite curving modification of the last stage stator cascade is carried out. The influence of the positive curving and the composite curving on the flow field is compared by numerical simulation. The results show that within the scope of this study, the reduction amplitude of total pressure loss coefficient of composite curved blade is about 1.10 times that of positive curved blade, and the increasing amplitude of total to static efficiency is about 1.16 times that of positive curved blade. The composite curving modification greatly improves the turbine performance. The research results provide guidance for the design of high-performance turbine blades.</p>