Multi-focus image fusion is an important aspect in the field of image fusion.The method of wavelet analysis promotes the research on multi-focus image fusion.The concept of multi-focus image fusion and ordinary image fusion methods are introduced,then the principle of image wavelet decomposition,the process of multi-focus image fusion by using wavelet analysis and different fusion rules are presented.The evaluation standard of fusion effect is analyzed,and simulations are carried out for quantitative analysis and comparison.Conclusions are given in the end.