The invention discloses a centrifugal blower vane designed based on a load method. A traditional design method for vane molded lines frequently depends on engineering experience, and blindness exists. According to the centrifugal blower vane, the load method is used for optimizing an original model vane and includes the steps that firstly, a proper average relative velocity curve is selected; then, multiple groups of load distribution functions are obtained by setting changes of loads at different positions; and afterwards, a vane molded line is determined according to load distribution. The performance of a blower can be improved through the obtained vane, a model with the middle load ratio being 0.7 is better in performance, especially under rated working conditions and small-flow working conditions, the efficiency under large-flow working conditions is gradually improved along with increasing of the load ratio, and the efficiency under the small-flow working conditions is reduced; flow in the optimized model is more stable than that in the original model, and no obvious flow separation and vortex exist; and in addition, due to the fact that no influence of separation exists, static pressure is stably increased in a vane channel, and a jet-wake structure at the position of an outlet of the vane channel is also improved.