The invention discloses an in-situ hybridization detection kit, which comprises a hybridization probe and a marker, and further discloses a method utilizing the in-situ hybridization detection kit to detect the Gankyrin gene RNA expression change, which is closely related with the pathologic evolution in the early stage of cancer. The method comprises the following steps: (1) under a condition that a hybridization probe and a target sequence can form a stable hybridization complex, contacting RNA to be detected in a substrate with a hybridization probe so as to form a hybridization complex; (2) detecting the obtained hybridization complex. The provided kit and detection method can detect the expression quantity of Gankyrin gene in the RNA level, can detect the cancer in an earlier stage compared with the medical imaging technology and conventional clinical biochemical index detection, can achieve real RNA level screening in the early stage of cancer, moreover, have the advantages of simpleness, convenience, and low cost, and thus are convenient to promote and use in county / district hospitals.