Provided is a tumor-treating pharmaceutical composition used in combination therapy of lenvatinib and (6S,9aS)-N-benzyl-8-({6-[3-(4-ethylpiperazin-1-yl)azetidin-1-yl ]pyridin-2-yl}methyl)-6-(2-fluoro-4-hydroxybenzyl)-4,7-dioxo-2-( prop-2-en-1-yl)hexahydro-2H-pyrazino[2,1-c][1,2,4]triazin-1(6H)- carboxamide.Se proporciona una composición farmacéutica para tratar un tumor, que se usa en terapia de combinación de lenvatinib y (6S, 9aS)-N-bencil-8-({6-[3-(4-etilpiperazin-1-il)azetidin-1-il]piridi n-2-il}metil)-6-(2-fluoro-4-hidroxibencil)-4,7-dioxo-2-(prop-2-en -1-il)hexahidro-2H-pirazino[2,1-c] [1,2,4]triazin-1(6H)-carboxamid a.