In order to solve the problem of the low efficiency of the traditional horizontal sedimentation tank, the paper carried out the study on the settlement effect of a new type of double-deck horizontal flow sedimentation tank in the water of high turbidity. This study designed three tank model : to flow inclined plate structure under double-deck horizontal flow sedimentation tank (model A), to the flow on the inclined plate tectonic double-deck horizontal flow sedimentation tank (model B) and tandem double-deck horizontal flow sedimentation tank (model C) , based on the three tank model in high turbidity to shed not adding flocculants compared with adding flocculant experiment, analysis of new double-decker advection sedimentation tank with existing tandem double-deck horizontal flow sedimentation tank for high turbidity flow sedimentation effect, analyze the effect of the settlement of the three tank found three tank next to the flow inclined plate tectonic double-deck horizontal flow sedimentation tank settlement work best. At present, the data about double-deck horizontal flow sedimentation tank model test research is less, in this paper, through theoretical analysis and model test for the new double-deck horizontal flow sedimentation tank based on the use of high turbidity to flow region to provide theoretical basis.