The disclosure provides a chemiluminescence detector. The chemiluminescence detector includes a reagent storage device, configured to store a reagent; a reaction device, configured to support a plurality of support reaction containers and perform a sample adding operation, a reagent adding operation and an incubating operation, the reaction device including a reaction outer disc mechanism configured to support the reaction containers and perform the reagent adding operation and an uniform mixing operation and a reaction inner disc mechanism configured to support the reaction containers and perform the incubating operation; a reagent storage device, a separate injection device, a cleaning device and a measuring device are arranged around an outer periphery side of the reaction outer disc mechanism. In this way, the operations on the reaction outer disc mechanism and the reaction inner disc mechanism is able to be performed simultaneously and are not interfered, so the detection speed of the chemiluminescence detector is improved.