The invention discloses a solar thermal chemical absorption reaction device and system. The device comprises a heat collection tube unit and a heat collector unit, wherein the heat collection tube unit comprises an inner tube, a coating film absorption tube and a transparent tube; a catalyst bed layer is arranged between the coating film absorption tube and the inner tube. The invention provides the solar thermal chemical absorption reaction device and system, process temperatures of a thermal chemical reaction layer (that is, the catalyst bed layer), are adjusted through heat storage and release of the inner tube, variation of the process temperatures of the catalyst bed layer can be reduced, the process temperatures of the catalyst bed layer can be uniformly distributed in an axial direction of a casing, due to uniform distribution of the process temperatures of the catalyst bed layer, the utilization efficiency of a catalyst can be improved, and the utilization efficiency of the reaction device upon solar energy can be improved. Meanwhile, integral utilization of solar energy and external heat sources can be facilitated, and due to complementary utilization of thermochemistry, efficient utilization of the solar energy and the external heat can be achieved.