In order to improve the impact resistance of shipboard equipment in service， it is necessary to install an impact isolation device between the ship and shipboard equipment. For a kind of parallel coupling isolation device composed of multi-rod， Firstly， one dynamic theoretical model is established based on the coordinate transformation matrix by using screw theory and the basic principle of multi-dimensional impact isolation. Then， the regular modal matrix transformation was used to solve the dynamic equation. The analytical solutions of free response and forced response of the multi-rod impact isolation device were obtained， which were compared with the simulation results of ADAMS. Finally， the drop-type impact test was carried out on the multi-rod impact isolation device. The results show that the multi-rod impact isolation device can effectively isolate the strong impact load under the standard specifications. Moreover， the isolation rate of transverse and longitudinal impact is up to 97.79%， and the vertical impact is up to 95.34%. The high agreement between the simulation results and analytical results indicates the validity of the analytical results. The difference between test and simulation response is about 3%， and the impact isolation rate increases with the increase of impact load， indicating that the device still has good impact resistance under strong impact environment. The results provide theoretical reference and data basis for the impact isolation of shipborne equipment by multi rod impact isolation device.