The invention discloses a gene-detection integrally completed enclosed PCR (polymerase chain reaction) amplification tube which comprises a tube body, a solution storage tank and a tube cover, wherein the tube body is used for accommodating a PCR buffer solution, the solution storage tank is used for accommodating a hybridized buffer solution, the tube cover encloses an opening on the upper side of the solution storage tank, the solution storage tank is placed at the upper part of the tube body, the upper end of the solution storage tank is hermetically connected with the upper end of the opening of the tube body, the bottom surface of the solution storage tank is provided with a communicating tube for communicating the upper and lower sides of the bottom surface, and the lower end of the communicating tube is connected with the bottom surface. According to the invention, PCR, gene hybridization and gene detection can be completed in an enclosed system, thereby avoiding cross contamination; and PCR amplification system is completely isolated from a DNA hybridization system, thereby avoiding the influence of compositions such as buffer solutions and enzyme and the like in the amplification system on hybridization reaction, and greatly improving the accuracy and repeatability of gene detection. Due to the tube cover of the enclosed PCR amplification tube disclosed by the invention, the sample adding is more convenient, the tightness is strong, and the detection accuracy is better.