Olefin block copolymers (OBCs) are novel thermoplastic elastomers (TPEs) consisting of alternative hard and soft segments. The microstructure regulation and property optimization for OBCs through industrial processing are of great significance1,2. In our work, Olefin block copolymers (OBCs) with different ethylene content were selected to investigate the crystallization behavior and mechanical performance when blending with small amount of long-chain homopolymer (UHMWPE). Melt blended samples showed micro-sized UHMWPE aggregates and isolated crystallization for UHMWPE and OBCs. The enhancement for mechanical performance was thus limited. However, molecular-level dispersion of UHMWPE can be achieved when using solution blending. These solution blended OBC samples showed accelerated crystallization and significantly reduced crystal size. The DSC curves even showed a co-crystallization behavior. As a result, significant improvement of Young’s modulus and tensile strength was thus achieved. The long-chain homopolymer (UHMWPE) mainly play a role of “tie” effect in connecting different crystallized segments. On the other hand, melt drawing (with tunable stretch ratio) was also conducted to tune the crystal structure in OBCs. At low stretch ratio, OBCs showed a complete rubber behavior with extremely high elongation at break. When increasing the stretch ratio, the Young’s modulus and tensile strength increases while the elongation at break and elastomeric property decreases. More interestingly, shish-kebab-like structure could be achieved for OBC films obtained with higher stretch ratio. The fracture mechanism for samples with different stretch ratios will be investigated in our future work. Therefore, blending and processing are efficient approaches for structural control and large enhancement of mechanical performance of OBC.