A ceiling light apparatus, comprising: a fixing bracket (10, 601, 652, 882) to be fixed on a ceiling, wherein the fixing bracket (10, 601, 652, 882) has a first end (11, 602, 8822), a main part (603, 8821) and a second end (12, 604, 8823); a main housing (20, 607, 881, 8841) comprising a back cover (203, 611), wherein the back cover (203, 611) has a first connector (21, 605) and a second connector (40, 606, 884), when the main housing (20, 607, 881, 8841) is to be attached to the fixing bracket (10, 601, 652, 882), the first end (11, 602, 8822) is firstly attached to the first connector (21, 605) and then the first end is rotated with respect to the first connector (21, 605) to move the second end (12, 604, 8823) to approach to the second connector (40, 606, 884) for elastically locking the second end (12, 604, 8823) to the second connector (40, 606, 884); and a light source (201, 609) enclosed by the main housing (20, 607, 881, 8841) for emitting a light via a light opening of the main housing (20, 607, 881, 8841), wherein the first end (11, 602, 8822) is a hook (40, 8843), the first connector (21, 605) is a shaft, the hook (40, 8843) is held by the shaft when the main housing (20, 607, 881, 8841) is rotated with respect to the fixing bracket (10, 601, 652, 882), characterized in that the second connector (40, 606, 884) has an elastic unit (60, 8844) connected to a button (50, 52, 614) and comprising a spring with a hook (40, 8843) for locking the second end (12, 604, 8823) of the fixing bracket (10, 601, 652, 882), when the button (50, 52, 614) is pressed, the second end (12, 604, 8823) of the fixing bracket (10, 601, 652, 882) is released from the second connector (40, 606, 884). a fixing bracket (10, 601, 652, 882) to be fixed on a ceiling, wherein the fixing bracket (10, 601, 652, 882) has a first end (11, 602, 8822), a main part (603, 8821) and a second end (12, 604, 8823); a main housing (20, 607, 881, 8841) comprising a back cover (203, 611), wherein the back cover (203, 611) has a first connector (21, 605) and a second connector (40, 606, 884), when the main housing (20, 607, 881, 8841) is to be attached to the fixing bracket (10, 601, 652, 882), the first end (11, 602, 8822) is firstly attached to the first connector (21, 605) and then the first end is rotated with respect to the first connector (21, 605) to move the second end (12, 604, 8823) to approach to the second connector (40, 606, 884) for elastically locking the second end (12, 604, 8823) to the second connector (40, 606, 884); and a light source (201, 609) enclosed by the main housing (20, 607, 881, 8841) for emitting a light via a light opening of the main housing (20, 607, 881, 8841), wherein the first end (11, 602, 8822) is a hook (40, 8843), the first connector (21, 605) is a shaft, the hook (40, 8843) is held by the shaft when the main housing (20, 607, 881, 8841) is rotated with respect to the fixing bracket (10, 601, 652, 882), characterized in that the second connector (40, 606, 884) has an elastic unit (60, 8844) connected to a button (50, 52, 614) and comprising a spring with a hook (40, 8843) for locking the second end (12, 604, 8823) of the fixing bracket (10, 601, 652, 882), when the button (50, 52, 614) is pressed, the second end (12, 604, 8823) of the fixing bracket (10, 601, 652, 882) is released from the second connector (40, 606, 884).