In high-level vibration application scenarios, the cantilever beam structure of the infrared detector-dewar assembly is easily damaged. A non-contact helical spring support ring structure is designed. Between the dewar shell and the cold finger, the dewar heat leakage increased by the traditional strengthening scheme is greatly reduced through a non-contact method, and the vibration energy is converted into elastic potential energy, thereby reducing the stress impact of high-level vibration on the cold head. After simulation analysis and optimization with Ansys software, the maximum deformation of the platinum-iridium wire is 1.7 mm, which is 57.5% lower than the conventional structure; the maximum stress decreases by 52% to 307 MPa. Experimental results show that the average heat leakage after optimization increased by only 1%, while having significantly improved vibration resistance. The assemblies with conventional structures would experience platinum-iridium wire breakage after enduring 15 grms durable random vibration, while the optimized assemblies can withstand 15 grms durable random vibration and 17.6 grms short-term high-level random vibration. The optimized assemblies keep the detector focal plane temperature stable during 17.6 grms random vibration without affecting their normal operation.