The invention provides a robot-based permanganate index analyzer. The robot-based permanganate index analyzer is characterized by comprising a work platform, a sample moving mechanism and a reagent adding mechanism, wherein the work platform comprises a sample area, a heating reaction area and a titration area; the sample moving mechanism performs three-dimensional motion in the work platform andpicks and places samples in the work platform to specific work positions according to specific workflow; the reagent adding mechanism moves in the heating reaction area and the titration area and addsspecific reagents to the samples placed in the work range of the reagent adding mechanism according to specific workflow; the samples and the reagents are mixed and react in the heating reaction area; a detection mechanism in the titration area judges color change of the samples, so that the end point of the reaction is judged. The robot-based permanganate index analyzer is high in precision, andthe problems of errors caused by manual detection and the like can be solved.