The invention discloses a Krebs-type polyacid compound and a preparation method thereof. Based on a unit {SbW9}, the Krebs-type polyacid compound Na2Mn2H6[Mn2(H2O)2(trz)2(SbO2)2(SbW9O33)2] is synthesized by self-assembly of 1,2,4-triazole and transition metal, and during the reaction, Sb(III) is partially oxidized to Sb(V). According to the invention, the structural characteristics of polyoxometallate and the biological effect of anti-tumor activity are utilized, and organic groups are introduced into a polyoxometallate (POM) framework to change the surface charge, polarity and oxidation-reduction characteristics of the POM framework, so that the functional POM with lower toxicity and higher cell penetration capacity is formed, and the prepared Krebs-type polyacid compound has an inhibition effect on tumor cells, shows high anti-tumor activity on gastric cancer cells, and can be used as an anti-tumor medicine.