The effects of different catalysts on the curing sequences of bisphenol A‐aniline benzoxazine (BA‐a)/N,N′‐(2,2,4‐trimethylhexane‐1,6‐diyl) bis (maleimide) (TBMI) blends were studied, and the influence of curing sequences on the phase structure and properties of products was discussed. In BA‐a/TBMI/adipic acid, BA‐a homopolymerized first, followed by the copolymerization between TBMI and ring‐opened benzoxazine. This curing sequence led to strong copolymerization, which limited the movement of components and resulted in homogeneous structures of the final products. However, in BA‐a/TBMI/imidazole, TBMI homopolymerized firstly, followed by the homopolymerization of BA‐a. BA‐a and TBMI hardly copolymerized, and the products presented phase‐separated (bi‐continuous phase) structures finally. The degree of copolymerization and phase structures of products differed due to different curing sequences when different catalysts were used. Furthermore, the product with phase‐separated structures had improved thermal property and toughness compared to those of the product with homogeneous structures.