Hydraulic jump is of fast altering flow type, within which a critical flow transforms into a subcritical flow, and such alteration occurs within a relatively short path of the channel. In the present study, the impact of lateral angles of trapezoidal channel walls in the continuous form on the relative loss of hydraulic jump energy is investigated. For this purpose, the meta-heuristic harmony search algorithm is used for declaring the continuous lateral angles within the range of 45°–75°. With regard to the hydraulic definition for the hydraulic jump phenomenon, the harmony search algorithm, which is widely used for optimization and continuous problems, is considered as a simple concept of a useful algorithm. The results demonstrated the high efficiency of harmony search in the optimization of hydraulic problems. The highest value of jump energy loss up to 81% was recorded for the angle of 45°, implying the high efficiency of this section. As can be clearly seen in the results, the amount of destructive energy loss of hydraulic jump in the meta-heuristic algorithm is significantly higher than other previous methods.