The utility model relates to a two-stage shock-damper of a bicycle seat, which is characterized in that the two-stage shock damper is provided with a fixed support pipe 1 and a telescopic sliding pipe 3. The proper position of the fixed support pipe 1 is provided with a pin hole, and the telescopic sliding pipe 3 is provided with a long sliding trench hole 9. A spring transverse pin 2 can slide and be positioned up and down in the long sliding trench hole 9, and the inner of the telescopic sliding pipe 3 is provided with an adjustable spring 5, a pressure spring sliding block 6 and a pressure spring adjusting screw 7. The lower end of the adjustable spring 5 is provided with a bearing spring block 4, and the lower part of th fixed support pipe 1 is provided with a relay buffer spring 8. The utility model has the advantages of safe riding and comfort.