Abstract: Experiment study on small channels oscillation in density lock is carried out.The invalidation of density lock is due to the stratified interface of one small channel going beyond during the process of oscil-lation,and a circulation is formed among small channels.Three solutions are proposed through the theoretical analysis: variability of diameter channels,reduction of pressure among channels and disturbance of homog-enization.According to these solutions,the density lock structures are designed and verified through experi-ment.The result shows that the variability of diameter channels would effect only when oscillation passed;the way of reducing pressure among channels would increase the length of density lock and the disturbance of homogenization could reduce the oscillation effectively.