Random walk algorithm with compulsive evolution (RWCE) was an effective method for the optimization of heat exchanger network with the advantage of simple evolutionary strategy and less control parameters. The RWCE algorithm had the capacity to jump out of the local optimal through continuously accepting the imperfect solutions

but its jumping efficiency was often limited by the step size. The global search ability of the algorithm was reduced. Therefore

a novel combined step size generation method was established by studying the step size distribution of RWCE algorithm and analyzing the mechanism of large step size assisted to jump out of local optimal

then a structure evolution strategy motivated by large step size was proposed. Finally

the validity of the proposed structure evolution strategy was verified by three cases. Compared with the literature results

the results showed that the structure evolution strategy motivated by large step size had a strong global search ability.