A Dissipative particle dynamics (DPD) simulations are performed to study the cooperative self-assembly of coilrodcoil triblock copolymers and nanoparticles in solution. The results show that, when the nanoparticle concentration exceeds a given value, the ternary systems can form a novel nanocage composed of two-end coil-caps and middle rod-linkers. The novel nanocage is very similar to the real bird cage and the captured nanoparticles like the bird. It is the first nanocage from the self-assembly of coilrodcoil triblock copolymers. This may be used for the release of drugs and fertilizers, or as nanoreactors.