The noise of HgCdTe medium-wave photoconductive devices was studied by vibration text table and spectrum analyzer. The random vibration experimental results showed that the noise measured in vibration environment increased linearly with the increase of vibration power spectrum density (PSD).The linear dependence can be divided into two parts. The coefficient is 32 μVHz1/2/g2 or 80 μVHz1/2/g2 with the vibration PSD of 0.01 g2/Hz as the kink point. In order to explain the experimental results, we suggested that the vibration energy is absorbed with a certain coefficient by HgCdTe material and transformed into thermal energy. This gives rise to an increased scattering of charge carriers by the phonons in the material, eventually produces an extra vibration noise in the device.