To overcome the shortcomings of the existing method in solving the 0-1 knapsack problems, an improved fireworks algorithm is proposed. After a mathematical model of the 0-1 knapsack problem is given, an improved fireworks algorithm is proposed to solve it. The main idea of the improved algorithm is as follows. The initialization of the basic fireworks algorithm is solved by using Kent chaotic map to make the initial position more uniform. The Sigmoid function is also introduced to get the gradual explosion radius to make the solution accurate and the search speed reach a certain balance. The resolving results of the typical test function and the 0-1 knapsack problem show that the improved fireworks algorithm has higher precision and more stable performance.