Abstract: This study presents a Bi-Evolutionary Algorithm (BEA) simulating the mechanism of human evolution. Bi-Evolutionary Algorithm system includes knowledge subsystem and biological subsystem. They are mutually independent and interactive. Biological subsystem is used to solve the specific problems and provide knowledge source for knowledge subsystem. Knowledge subsystem is used to optimize the solving knowledge for a certain type of problem and provide guidance on solving method for biological subsystem. The proposed algorithm is used to solve knapsack problems; its work process is explained in the experiments. As knowledge subsystem provides the optimal solving method, such that the solution quality of BEA for the knapsack problem is much better than that of many other optimization algorithms that simulate the nature evolution course of general creature and its solving time is minimized. BEA is an optimization algorithm with high solving efficiency.