Abstract: In order to determine the relationship between differentfilter functions in structural topological optimization, the paperfocuses on the filter function in the ICM method. For a filter function with the form of power functions, first the homogenization method and the least squares method are adopted to calculate the weight filter function and the stiffness filter function. Then the numerical simulation method is used to study the relationship between the weight filter function and the stiffness filter function. Finally, the concept of exponential coefficients of filter function is proposed, and the relation of the stiffness filter functionwith the weight filter function is obtained.