Detection mechanism for polymerase chain reaction and polymerase chain reaction device

A polymerase chain reaction device, comprising:

• a heating module for providing heat to a convection-type polymerase chain reaction in the device;
• the heating module including:
• a low-temperature heating sub-unit;
• a high-temperature heating sub-unit arranged under the low-temperature heating sub-unit;
• and
• a thermal insulation sub-unit arranged between the low-temperature heating sub-unit and the high-temperature heating sub-unit, for preventing the low-temperature heating sub-unit from absorbing radiation heat from the high-temperature heating sub-unit;
• and
• wherein central portions of the high-temperature heating sub-unit, the low-temperature heating sub-unit and the thermal insulation sub-unit form a reaction hole position for inserting a reaction tube;
• the polymerase chain reaction device further comprising a light shielding module for shielding light entering the reaction tube;
• the light shielding module including:
• an upper light shielding cover for shielding external visible light, and
• a lower light shielding door including an elastic part for biasing the lower light shielding door in a closed state, such that the lower light shielding door shields visible light from entering the reaction tube in the process that the reaction tube is inserted into a reaction hole position.