Abstract:One of the difficult problems to be solved in lightweight design for forging machine is how to satisfy the requirement of intended life.Considering the feature of working condition, material and structure of heading machine bed, the calculation method of the beds fatigue life was analyzed, and the algorithm and process of topology optimization were put forward under fatigue life constraint.In addition, a type of heading machine bed was taken as an example to realize the iteration process of topology optimization under the beds fatigue life constraint and testify the proposed algorithm, which could effectively integrate beds fatigue life with its topology optimization and redesign so as to meet the requirements of both light weight and intended life.