Natural rubber (NR)/chlorinated butyl rubber (CIIR) composites have been prepared by mechanical blending and molding. The vulcanization properties, mechanical properties, uniaxial tensile orientation properties, strain-induced crystallization (SIC) and damping behavior of the composites were analyzed. Transmission electron microscopy (TEM) showed that CIIR components had an island structure distribution in the blends, and the boundaries were clear. With the increasing CIIR content, the compressive stress-strain properties were similar to those of pure NR, but the tensile strength decreased significantly compared with pure NR. Infrared dichroism analysis showed that the orientation behavior is mainly due to the NR component. Synchrotron radiation wide-angle X-ray diffraction (WAXD) analysis showed that the higher the proportion of CIIR, the weaker the SIC behavior. NR/CIIR blends with the characteristics of both precursors can be prepared by mechanical blending. The loss factor at 30 Hz increases from 0.1 for NR pure rubber to 0.18 for a 50/50 NR/CIIR blend, with an increase of 80%. This work provides new ideas for the preparation of rubber composite materials for shock insulation.