A slim linear LED lighting device (1, 1a, 1b, 1c, 1d, 1e), comprising: a printed circuit board (20, 20a, 20b, 20c, 20d, 20e) of which an upper layer is provided with a connecting circuit; at least one power input component; and a plurality of LED Bars (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y); wherein the said at least one power input component and the said plurality of LED Bars (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g 30h, 30j, 30k, 30p, 30w, 30y) are mounted on the said printed circuit board (20, 20a, 20b, 20c, 20d, 20e), the said LED Bars (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) are linearly arranged on the said printed circuit board (20, 20a, 20b, 20c, 20d, 20e), and electrically connected to the said power input component through the said connecting circuit provided on the said printed circuit board (20, 20a, 20b, 20c, 20d, 20e); wherein each LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) comprises a plurality of the same kind of LED chips (33, 331, 332, 333, 334) arranged linearly and apart equidistantly on an upper layer of a substrate (31, 31a, 31b) in a spacing of 0.2 mm to 3.0 mm; wherein the said substrate (31, 31a, 31b) has electrically conductive layers on the upper layer and the bottom layer to enable the said LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) to be mounted on the printed circuit board (20, 20a, 20b, 20c, 20d, 20e) by SMT process; wherein each LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) comprises a slim strip-shaped condensing lens (371, 372, 373, 374, 375) structure, whereby the slim strip-shaped condensing lens structure is a molding lens formed by packaging the LED bar by a molding process, so that the beam angle of the said LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j 30k, 30p, 30w, 30y) perpendicular to the longitudinal direction that the plurality of LED chips (33, 331, 332, 333, 334) are lined up is condensed to be between 10 and 80 degrees, and the slim strip-shaped condensing lens (371, 372, 373, 374, 375) structure is integrally formed in the said LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) by said molding process during a package process and fully covers all LED chips (33, 331, 332, 333, 334) in the said LED Bar (30, 30a, 30b, 30c, 30d 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y). a printed circuit board (20, 20a, 20b, 20c, 20d, 20e) of which an upper layer is provided with a connecting circuit; at least one power input component; and a plurality of LED Bars (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y); wherein the said at least one power input component and the said plurality of LED Bars (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g 30h, 30j, 30k, 30p, 30w, 30y) are mounted on the said printed circuit board (20, 20a, 20b, 20c, 20d, 20e), the said LED Bars (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) are linearly arranged on the said printed circuit board (20, 20a, 20b, 20c, 20d, 20e), and electrically connected to the said power input component through the said connecting circuit provided on the said printed circuit board (20, 20a, 20b, 20c, 20d, 20e); wherein each LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) comprises a plurality of the same kind of LED chips (33, 331, 332, 333, 334) arranged linearly and apart equidistantly on an upper layer of a substrate (31, 31a, 31b) in a spacing of 0.2 mm to 3.0 mm; wherein the said substrate (31, 31a, 31b) has electrically conductive layers on the upper layer and the bottom layer to enable the said LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) to be mounted on the printed circuit board (20, 20a, 20b, 20c, 20d, 20e) by SMT process; wherein each LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) comprises a slim strip-shaped condensing lens (371, 372, 373, 374, 375) structure, whereby the slim strip-shaped condensing lens structure is a molding lens formed by packaging the LED bar by a molding process, so that the beam angle of the said LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j 30k, 30p, 30w, 30y) perpendicular to the longitudinal direction that the plurality of LED chips (33, 331, 332, 333, 334) are lined up is condensed to be between 10 and 80 degrees, and the slim strip-shaped condensing lens (371, 372, 373, 374, 375) structure is integrally formed in the said LED Bar (30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y) by said molding process during a package process and fully covers all LED chips (33, 331, 332, 333, 334) in the said LED Bar (30, 30a, 30b, 30c, 30d 30e, 30f, 30g, 30h, 30j, 30k, 30p, 30w, 30y).