The invention relates to a kit for predicting colorectal cancer liver metastases and a use method. The kit includes a DNA database building kit, the DNA database building kit comprises probes of a plurality of genes, and the plurality of genes include: high risk genes: KRAS, BRAF, MLH1, NRAS, MSH2, PMS2, UGT1A1, MSH6 AKT1, PIK3CA, PTEN, SMAD4, TP53, NM23, TIAM1, MTS1; and low risk genes: PRKDC, RAD50, STAG2, XRCC5, XRCC6, FANCA, ATR, MUTYH, EMSY, ERCC4, RAD51, PARP1, XRCC1. The kit provided by the invention performs related mutation detection on colorectal cancer liver metastases related genes in peripheral blood, and combines specific scoring mechanism to rapidly and conveniently judge and predict colorectal cancer liver metastases.