With on-site hoisting pallet of sintering material to carry out multi regional research,the reason of decline in sinter quality in deep sintering bed and high ratio imported ore of Jingtang was discovered as followed : Constraint problems of sinter quality of deep sintering bed and high ratio imported ore were discovered as follows : ① Materials size.Low part material of l# machine is course,and segregation is too large,resulting in less flux in low part;horizontal material distribution is not uniform in 2#machine pallet from one side to the other.② Component.For 1# machine,flux segregation is mainly distributed in high part,and material in low part has coarse granularity and less flux.and C segregation are increased;For 2# machine,chemical composition and the content of C is not even the linearity segregation,in second layer segregation abnormalities,monotonely only in Si02 and A1203 content segregation.③ High temperature zone.Width and speed of flame front along the width of pallet showed some inhomogeneities.④ Phase.Calcium ferrite content is lower in low part.⑤ Except surface,along the bed height,sinter tumbler index and yield index is not necessarily more and higher,and instead size degradation degree is more and more large.Based on this,the proposal of optimizing process and ore blending were proposed as follows : ①for l# machine,taking a cut of large size particle ( from 20% t0 8% ),eventually making the lateral upper material distribution tends to be uniform,with mean particle size standard deviation reducing from 0.32 t0 0.16;grain size segregation changes from 0.33 mm/( 100 mm) t0 0.27 mm/( 100 mm);drum index increases 2.1%,after falling,power reduced 1.73 0-10,size degradation is reduced by an average of 4.41 %.② for 2# machine,adopting the optimum mixing machine (88 HZ t0 78 HZ) and nine roller speed (22 HZ t0 18 HZ),increasing the quantity of return mines ( 10% ),optimization of shuttle car spacing and stopping time transformation,the mixture ratio of < 3 mm increased 8.5 percentage points;on the horizontal direction,the material distribution tends to be uniform;and the grain size segregation changes from 0.23 mm/( 100 mm) t0 0.30 mm/( 100 mm).Suitable mixture segregation in Jingtang is 0.26 -0.30 mm/(100 mm).Finally,this research is helpful for improving lower sinter quality in the thick material layer,providing quantitative analysis on large sintering machine region material and sinter properties,and mastering relations between large sintering equipment of sintering mixture and the final quality of sintered ore matching.Sinter quality improved with sinter tumbler index increasing by 0.2% - 0.49%,5 - 10 mm decreasing 0.2 - 0.69 percentage points,and sinter yield increasing by 1.67 %.