With the analysis of the axial force of every bar in intelligent truss,this paper deduced the piezoelectric truss node displacement,and then transformed the multi-objective optimization to the single objective optimization by the method of random weight.Based on the wheel selection,the selection operator was improved,and then the improved genetic algorithm was used to solve the multi-objective optimization.At last,this paper optimized the actuator and number of the 12 bars intelligent truss by this method.The results show that the actuator should be fixed on the number 1 bar,so we can know that the method of random weight and improved genetic algorithm can be used in the optimization of the intelligent truss,and those methods are effective.By comparison with the method of fixed weight,this method can avoid subjectivity.