A gene sequencing reaction device, a gene sequencing system and a gene sequencing reaction method. The gene sequencing reaction device includes: a supporting platform; a dipping container disposed on the supporting platform, wherein the dipping container has a dipping reaction area, and the dipping reaction area is configured to hold a chemical reagent for gene sequencing reaction, so as to dip a sequencing chip having a DNA sample loading structure on the surface and having a DNA sample loaded thereon in the chemical reagent to perform a gene sequencing reaction; a temperature control apparatus, configured to control the temperature of the chemical reagent in the dipping reaction area; and a transfer apparatus, configured to insert the sequencing chip into the dipping reaction area or pull out the sequencing chip from the dipping reaction area.