The invention mainly elaborates application of QSER1 protein as a biomarker for diagnosis and prognosis of multiple tumors in multiple tumors and a method. The present invention describes the diagnosis of QSER1 in predicting a variety of cancers, such as liver cancer, sarcoma, kidney cancer, gastric adenocarcinoma, pheochromocytoma and parangganglioma, pancreatic cancer, breast cancer, gastric cancer, and the like. The invention further constructs shRNA (short hairpin Ribonucleic Acid) capable of specifically interfering with QSER1 gene expression, plasmids capable of interfering with QSER1 gene expression, lentiviruses capable of interfering with QSER1 gene expression and an antibody capable of specifically recognizing QSER1. The plasmid with the specific shRNA sequence and the lentivirus provided by the invention can reduce the expression level of the QSER1 gene, so that the growth of cells and the formation of cell clone can be inhibited, the apoptosis of tumor cells can be promoted, and the plasmid and the lentivirus have great significance in diagnosis and treatment of tumors. According to research results of the invention, a kit for diagnosis and prognosis prediction of various cancers can be developed, and the kit has a wide clinical application prospect.