The invention relates to mixed denim and a technique for producing the same. The technique is as follows: firstly, multi-color segment dyeing yarns are adopted to be arranged and combined into bottom colored flower patterns of the denim; secondly, a main fundamental color required by the denim is dyed for the second time on a surface layer of the denim yarns; thirdly, partial colors on the surface layer of the denim are locally peeled off and internal colors of the yarns and the bottom colored flower patterns of the denim are exposed, thereby the mixed effect that the boundary of the flower patterns is blurred and the color is soft is protruded. The technique for producing the mixed denim comprises the following steps of: production of the multi-color segment yarns, yarn mixing and warping, pretreatment, dyeing and sizing, weaving and after finishing. The mixed flower patterns reach the effects of roughness, rusticity, rich color, softness and naturalness, and the techniques such as flower production, dyeing, sizing and so on can be finished once simultaneously, thereby the technique reduces labor duplication, saves a great deal of energy and can obviously reduce the production cost and the pollution of the mixed denim and the multi-color segment dyeing yarns.