Abstract: Abstract: Artificial open channels are the major conveyance systems to deliver water. Computation of parameters of channel cross section is an important task in hydraulic design of open channels. From a hydraulic engineering perspective, it would be prefer to have an optimal method with reasonable mathematical model and high accuracy for designing the parameters of channel cross section. However, the optimization method of the channel cross section in northern Irrigation District with concrete lining only considers the reliability under single hydraulics conditions, while ignoring the safety of frost heaving and the economy. To optimize trapezoidal cross section structure with the concrete lining accurately, a mathematical model based on optimal hydraulic section, economy, and safety of frost heaving is solved by adaptive particle swarm optimization (APSO). The APSO is presented to overcome the problem of premature convergence and local optimal in conventional particle swarm optimization (PSO). With a reasonable assumption combined with the basic theory of mechanics, the constrained optimization model is propounded, which considers the thickness value of channel concrete slab simultaneously with the objective of cost minimization. The optimized channel section not only satisfies the optimal hydraulic cross section but guarantees the safety and stability of the side walls so that both the amount of the concrete lining and the land acquisition are optimized. Finally, the Xuexing main channel of Wokenhe Irrigation District in Heilongjaing Province is taken as an example to analyze the effects of design parameters, such as channel slope, width of channel bottom, height of channel on the objective function. The result shows that the parameters obtained by the APSO can minimize the lining cost and the land occupation under the condition of satisfying the optimum hydraulic section. Comparing the 12 continuous channel sections based on wetted perimeter, the reductions of the lining amount and the land occupation were 1.8% and 1.5% respectively with the low flow errors. For parameters, the optimum is less sensitive to the increase in bed width and more sensitive to the increase in side slope obviously. When the values of width and height of the channel increase, the objective function increases. The value of lining thickness is a comprehensive reflection of soil quality, negative temperature and status of moisture; thereby the objective function can be solved provided that freezing forces is determined according to the practical experience or experiment. The results obtained by APSO approach are satisfying and the method can be used reliably for the design of artificial open channels. The research can improve the level of concrete seepage channel optimization in cold region and provide a scientific basis for enhancing operation benefit in irrigation district.