The invention relates to a slurry bed reaction apparatus, comprising a reaction unit (101) and a separation unit (6), wherein the separation unit is located out of the reaction unit, communicated with the reaction unit and positioned at the backward position of the reaction unit, the separation unit (6) comprises at least one separator (11) and a condensation section (15), at least one part of the separator (11) is located in the condensation section (15), and separation is reinforced through condensation. The invention also provides a method for carrying out a slurry bed reaction by using the reaction apparatus.