Abstract: In order to ensure the structure of coal re-screening plant in Linhua coal preparation plant,the reason of resonance is analyzed by deciding vibration source,detecting natural vibration and forced vibration. The results show that resonance of beam-plate under equipment is caused by flexural stress from screens,what’s more,interfering frequency to structure of the plant,caused by equipment,is close to first modal frequency generated by vertical natural vibration of beam-plate,however,smaller rigidity of secondary beam directly supporting horizontal load and flexural stress,will increase dynamic response of the structure. For this reason,measures should be taken to strengthen rigidity of secondary beam and floor.