The energy consumption of a sludge transport pipeline system has been analyzed and optimization calculation performed using the GA-DE (Genetic Algorithm-Differential Evolution) hybrid algorithm for the design parameters of the system. The factors influencing the total cost of the sludge transport pipeline system were studied first. In this analysis, sludge concentration and transport velocity were chosen as the two key parameters and optimized using a genetic algorithm and evolutionary algorithms. Next, a sludge transport project at one urban sewage treatment plant in Changchun City, Jilin Province was modeled with respect to cost and the optimization of two key parameters was carried out. The results showed that the optimal values of sludge concentration C-w, transport velocity v and pipeline diameter D were 2.32%, 1.10 m/s and 300 mm, respectively, under the conditions of sludge quantity Q = 0.226-0.045 m(3)/s (sludge concentration C-w = 0.8-4.0%) and transport length L = 4.5 x 10(3) m. The total annualized cost W was 528,300 RMB under this scheme. The test example confirms that the GA-DE hybrid algorithm is feasible and highly efficient for the parameter design optimization of a sludge transport pipeline system. Finally, the bias curve of the specific total annualized cost was used for the selection of the optimization schemes for each of the sludge concentration partitions.