Provided in the present invention is a quinolinyl-substituted carboxylic acid compound as shown in formula (I) or a pharmaceutically acceptable salt thereof, and also disclosed are a preparation method and the use of the compound and a preparation comprising the quinolinyl-substituted carboxylic acid compound or a pharmaceutically acceptable salt thereof. The compound is an inhibitor of the protein kinase AXL and/or VEGFR2 and can be used for treating diseases caused by aberrant activity of both kinases, such as tumours, etc.本發明提供了一種如式(I)所示的一種喹啉基取代的羧酸化合物或其藥學上可接受的鹽,同時進一步公開了該化合物的製備方法及應用和含該喹啉基取代的羧酸化合物或其藥學上可接受的鹽的製劑。這類化合物是蛋白激酶AXL及/或VEGFR2的抑制劑,可用於治療因這兩種激酶活性異常所引起的疾病,例如腫瘤等。無