Abstract: In view of the light weight， small space and small amplitude requirements of electronic equipment for vibration isolation structure， the paper focuses on the isolation of low frequency vibration from its base. By introducing the cross‑braced configuration， a concave cross braced plate model is proposed， the influence law of structural parameters on its low frequency vibration isolation performance is illustrated. Then， based on the design concept of cross‑bracing， a concave sandwich phononic crystal structure model is proposed， and the influence mechanism of geometric parameters on its frequency response characteristics is revealed. After geometric parameter optimization and experimental verification， the vibration isolation structure model has excellent vibration attenuation characteristics in the low and wide frequency band. In 100~500 Hz， the attenuation efficiency of acceleration power spectral density above 70%. In 35~80 Hz， and 500~2000 Hz， the attenuation efficiency of acceleration power spectral density above 40%. Working displacement of the vibration isolation structure under 3 times standard deviation confidence is less than 3 mm. Therefore， it is suitable for the isolation of low frequency random vibration. In addition， the model has broad application prospects owing to its advantages of light weight， small volume， large bearing capacity and strong universality.