Control of the overall morphology and inner structure of multicompartment micelles from binary blends of triblock copolymers in solution was studied by dissipative dynamics simulations. The effects of the block sequence, block ratio, block length, and chain architecture on the morphology and structure of mixed multicompartment micelles were investigated systematically. This work shows that by changing the block composition or chain architecture of one copolymer in the binary blends, the mixed degree, relative distance, and degree of participation of core-forming blocks from two triblock copolymers can be tuned, and diverse morphologies of mixed micelles with alterable domain arrangements and overall size can be obtained. This work shows that blending of copolymers is an effective way to control the morphology and inner structure of multicompartment micelles, providing useful information on the preparation of mixed micelles with unique properties for practical applications.