Provided is a light-emitting device for a display, and a method that includes light sources distributed on one or more strips, several light sources are arranged on each strip, and are electrically connected in a matrix manner, the number of rows and columns of the matrix are greater than 1, and each row and column of the matrix have a control line to receive a control signal; and a control unit that acquires a video signal to be provided to the display screen, from a signal source of the display screen, determines color and brightness of each light source according to the video signal, wherein each light source corresponds to a partial pixel area in the outermost periphery of a display area, and for each matrix, sequentially control each row or column of light sources in the matrix to emit light based on color and brightness within one light-emitting period.