A modularized lighting device includes a lighting module and a frame. The lighting module includes a housing and two end caps disposed at the two ends of the housing respectively. Each of the end caps includes a base having an accommodating space and two connecting sheets fixed at the bottom of the accommodating space. The frame includes two electrical connecting modules. Each of the electrical connecting modules includes an installation base having an installation space and two clamping structures disposed at the bottom of the installation space. The two end caps are detachably installed at the two electrical connecting modules respectively, such that the two connecting sheets of each of the end caps are inserted into the two clamping structures of the electrical connecting module corresponding thereto.